CWE

Common Weakness Enumeration

A community-developed list of SW & HW weaknesses that can become vulnerabilities
New to CWE? click here!
CWE Most Important Hardware Weaknesses
CWE Top 25 Most Dangerous Weaknesses
Home > CWE List > CWE-307: Improper Restriction of Excessive Authentication Attempts (4.18)
ID
CWE Glossary Definition

CWE-307: Improper Restriction of Excessive Authentication Attempts

Weakness ID: 307
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.
View customized information:
For users who are interested in more notional aspects of a weakness. Example: educators, technical writers, and project/program managers. For users who are concerned with the practical application and details about the nature of a weakness and how to prevent it from happening. Example: tool developers, security researchers, pen-testers, incident response analysts. For users who are mapping an issue to CWE/CAPEC IDs, i.e., finding the most appropriate CWE for a specific issue (e.g., a CVE record). Example: tool developers, security researchers. For users who wish to see all available information for the CWE/CAPEC entry. For users who want to customize what details are displayed.
×

Edit Custom Filter


Description
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame. Diagram for CWE-307
Common Consequences
Section HelpThis table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Impact Details

Bypass Protection Mechanism

Scope: Access Control

An attacker could perform an arbitrary number of authentication attempts using different passwords, and eventually gain access to the targeted account using a brute force attack.
Potential Mitigations
Phase(s) Mitigation

Architecture and Design

Common protection mechanisms include:

  • Disconnecting the user after a small number of failed attempts
  • Implementing a timeout
  • Locking out a targeted account
  • Requiring a computational task on the user's part.

Architecture and Design

Strategy: Libraries or Frameworks

Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].

Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]
Relationships
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
Relevant to the view "Research Concepts" (View-1000)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 799 Improper Control of Interaction Frequency
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 1390 Weak Authentication
Relevant to the view "Software Development" (View-699)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1211 Authentication Errors
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-1003)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 287 Improper Authentication
Relevant to the view "Architectural Concepts" (View-1008)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1010 Authenticate Actors
Modes Of Introduction
Section HelpThe different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.
Phase Note
Architecture and Design COMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.
Applicable Platforms
Section HelpThis listing shows possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.
Languages

Class: Not Language-Specific (Undetermined Prevalence)

Demonstrative Examples

Example 1


In January 2009, an attacker was able to gain administrator access to a Twitter server because the server did not restrict the number of login attempts [REF-236]. The attacker targeted a member of Twitter's support team and was able to successfully guess the member's password using a brute force attack by guessing a large number of common words. After gaining access as the member of the support staff, the attacker used the administrator panel to gain access to 33 accounts that belonged to celebrities and politicians. Ultimately, fake Twitter messages were sent that appeared to come from the compromised accounts.

Example 1 References:
[REF-236] Kim Zetter. "Weak Password Brings 'Happiness' to Twitter Hacker". 2009年01月09日. <https://www.wired.com/2009/01/professed-twitt/>. URL validated: 2023年04月07日.


Example 2


The following code, extracted from a servlet's doPost() method, performs an authentication lookup every time the servlet is invoked.

(bad code)
Example Language: Java
String username = request.getParameter("username");
String password = request.getParameter("password");

int authResult = authenticateUser(username, password);

However, the software makes no attempt to restrict excessive authentication attempts.



Example 3


This code attempts to limit the number of login attempts by causing the process to sleep before completing the authentication.

(bad code)
Example Language: PHP
$username = $_POST['username'];
$password = $_POST['password'];
sleep(2000);
$isAuthenticated = authenticateUser($username, $password);

However, there is no limit on parallel connections, so this does not increase the amount of time an attacker needs to complete an attack.



Example 4


In the following C/C++ example the validateUser method opens a socket connection, reads a username and password from the socket and attempts to authenticate the username and password.

(bad code)
Example Language: C
int validateUser(char *host, int port)
{
int socket = openSocketConnection(host, port);
if (socket < 0) {
printf("Unable to open socket connection");
return(FAIL);
}

int isValidUser = 0;
char username[USERNAME_SIZE];
char password[PASSWORD_SIZE];

while (isValidUser == 0) {
if (getNextMessage(socket, username, USERNAME_SIZE) > 0) {
if (getNextMessage(socket, password, PASSWORD_SIZE) > 0) {
isValidUser = AuthenticateUser(username, password);
}
}
}
return(SUCCESS);
}

The validateUser method will continuously check for a valid username and password without any restriction on the number of authentication attempts made. The method should limit the number of authentication attempts made to prevent brute force attacks as in the following example code.

(good code)
Example Language: C
int validateUser(char *host, int port)
{
...

int count = 0;
while ((isValidUser == 0) && (count < MAX_ATTEMPTS)) {
if (getNextMessage(socket, username, USERNAME_SIZE) > 0) {
if (getNextMessage(socket, password, PASSWORD_SIZE) > 0) {
isValidUser = AuthenticateUser(username, password);
}
}
count++;
}
if (isValidUser) {
return(SUCCESS);
}
else {
return(FAIL);
}
}


Example 5


Consider this example from a real-world attack against the iPhone [REF-1218]. An attacker can use brute force methods; each time there is a failed guess, the attacker quickly cuts the power before the failed entry is recorded, effectively bypassing the intended limit on the number of failed authentication attempts. Note that this attack requires removal of the cell phone battery and connecting directly to the phone's power source, and the brute force attack is still time-consuming.



Selected Observed Examples

Note: this is a curated list of examples for users to understand the variety of ways in which this weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.

Reference Description
the REST API for a network OS has a high limit for number of connections, allowing brute force password guessing
Product does not disconnect or timeout after multiple failed logins.
Product does not disconnect or timeout after multiple failed logins.
Product does not disconnect or timeout after multiple failed logins.
Product does not disconnect or timeout after multiple failed logins.
Product does not disconnect or timeout after multiple failed logins.
User accounts not disabled when they exceed a threshold; possibly a resultant problem.
Detection Methods
Method Details

Dynamic Analysis with Automated Results Interpretation

According to SOAR [REF-1479], the following detection techniques may be useful:

Highly cost effective:
  • Web Application Scanner
  • Web Services Scanner
  • Database Scanners
Cost effective for partial coverage:
  • Host-based Vulnerability Scanners - Examine configuration for flaws, verifying that audit mechanisms work, ensure host configuration meets certain predefined criteria

Effectiveness: High

Dynamic Analysis with Manual Results Interpretation

According to SOAR [REF-1479], the following detection techniques may be useful:

Highly cost effective:
  • Fuzz Tester
  • Framework-based Fuzzer
Cost effective for partial coverage:
  • Forced Path Execution

Effectiveness: High

Manual Static Analysis - Source Code

According to SOAR [REF-1479], the following detection techniques may be useful:

Highly cost effective:
  • Focused Manual Spotcheck - Focused manual analysis of source
  • Manual Source Code Review (not inspections)

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR [REF-1479], the following detection techniques may be useful:

Cost effective for partial coverage:
  • Source code Weakness Analyzer
  • Context-configured Source Code Weakness Analyzer

Effectiveness: SOAR Partial

Automated Static Analysis

According to SOAR [REF-1479], the following detection techniques may be useful:

Cost effective for partial coverage:
  • Configuration Checker

Effectiveness: SOAR Partial

Architecture or Design Review

According to SOAR [REF-1479], the following detection techniques may be useful:

Highly cost effective:
  • Formal Methods / Correct-By-Construction
Cost effective for partial coverage:
  • Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Effectiveness: High
Memberships
Section HelpThis MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
Nature Type ID Name
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 724 OWASP Top Ten 2004 Category A3 - Broken Authentication and Session Management
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 808 2010 Top 25 - Weaknesses On the Cusp
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 812 OWASP Top Ten 2010 Category A3 - Broken Authentication and Session Management
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 866 2011 Top 25 - Porous Defenses
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 884 CWE Cross-section
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 955 SFP Secondary Cluster: Unrestricted Authentication
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1353 OWASP Top Ten 2021 Category A07:2021 - Identification and Authentication Failures
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1396 Comprehensive Categorization: Access Control
Vulnerability Mapping Notes
Usage ALLOWED
(this CWE ID may be used to map to real-world vulnerabilities)
Reason Acceptable-Use

Rationale

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments

Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
PLOVER AUTHENT.MULTFAIL Multiple Failed Authentication Attempts not Prevented
Software Fault Patterns SFP34 Unrestricted authentication
References
[REF-45] OWASP. "OWASP Enterprise Security API (ESAPI) Project".
<https://owasp.org/www-project-enterprise-security-api/>. (URL validated: 2025年07月24日)
[REF-236] Kim Zetter. "Weak Password Brings 'Happiness' to Twitter Hacker". 2009年01月09日.
<https://www.wired.com/2009/01/professed-twitt/>. (URL validated: 2023年04月07日)
[REF-1218] Graham Cluley. "This Black Box Can Brute Force Crack iPhone PIN Passcodes". The Mac Security Blog. 2015年03月16日.
<https://www.intego.com/mac-security-blog/iphone-pin-pass-code/>.
Content History
Submissions
Submission Date Submitter Organization
2006年07月19日
(CWE Draft 3, 2006年07月19日) 		PLOVER
Contributions
Contribution Date Contributor Organization
2024年09月10日
(CWE 4.16, 2024年11月19日) 		Abhi Balakrishnan
Contributed usability diagram concepts used by the CWE team
Modifications
Modification Date Modifier Organization
2025年09月09日
(CWE 4.18, 2025年09月09日) 		CWE Content Team MITRE
updated Demonstrative_Examples, Detection_Factors, Potential_Mitigations, References
2024年11月19日
(CWE 4.16, 2024年11月19日) 		CWE Content Team MITRE
updated Common_Consequences, Description, Diagram
2023年06月29日 CWE Content Team MITRE
updated Mapping_Notes
2023年04月27日 CWE Content Team MITRE
updated Demonstrative_Examples, References, Relationships
2022年10月13日 CWE Content Team MITRE
updated Demonstrative_Examples, Description, Observed_Examples, References, Relationships
2021年10月28日 CWE Content Team MITRE
updated Demonstrative_Examples, References, Relationships
2020年08月20日 CWE Content Team MITRE
updated Related_Attack_Patterns
2020年02月24日 CWE Content Team MITRE
updated Detection_Factors, Relationships
2019年06月20日 CWE Content Team MITRE
updated Demonstrative_Examples, Relationships
2017年11月08日 CWE Content Team MITRE
updated Demonstrative_Examples, Modes_of_Introduction, Relationships
2014年07月30日 CWE Content Team MITRE
updated Detection_Factors, Relationships, Taxonomy_Mappings
2012年05月11日 CWE Content Team MITRE
updated Relationships
2011年09月13日 CWE Content Team MITRE
updated Potential_Mitigations, References, Relationships
2011年06月27日 CWE Content Team MITRE
updated Common_Consequences, Related_Attack_Patterns, Relationships
2011年06月01日 CWE Content Team MITRE
updated Common_Consequences
2011年03月29日 CWE Content Team MITRE
updated Demonstrative_Examples
2010年04月05日 CWE Content Team MITRE
updated Demonstrative_Examples
2010年02月16日 CWE Content Team MITRE
updated Demonstrative_Examples, Name, Potential_Mitigations, Relationships, Taxonomy_Mappings
2009年12月28日 CWE Content Team MITRE
updated Applicable_Platforms, Demonstrative_Examples, Potential_Mitigations
2009年07月27日 CWE Content Team MITRE
updated Observed_Examples
2009年03月10日 CWE Content Team MITRE
updated Relationships
2008年09月08日 CWE Content Team MITRE
updated Relationships, Taxonomy_Mappings
2008年07月01日 Sean Eidemiller Cigital
added/updated demonstrative examples
Previous Entry Names
Change Date Previous Entry Name
2008年04月11日 Multiple Failed Authentication Attempts not Prevented
2010年02月16日 Failure to Restrict Excessive Authentication Attempts
More information is available — Please edit the custom filter or select a different filter.
Page Last Updated: September 09, 2025

Use of the Common Weakness Enumeration (CWE™) and the associated references from this website are subject to the Terms of Use. CWE is sponsored by the U.S. Department of Homeland Security (DHS) Cybersecurity and Infrastructure Security Agency (CISA) and managed by the Homeland Security Systems Engineering and Development Institute (HSSEDI) which is operated by The MITRE Corporation (MITRE). Copyright © 2006–2025, The MITRE Corporation. CWE, CWSS, CWRAF, and the CWE logo are trademarks of The MITRE Corporation.

AltStyle によって変換されたページ (->オリジナル) /