CWE - CWE-96: Improper Neutralization of Directives in Statically Saved Code ('Static Code Injection') (4.18)

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CWE Glossary Definition

CWE-96: Improper Neutralization of Directives in Statically Saved Code ('Static Code Injection')

Weakness ID: 96

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.

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Description

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes code syntax before inserting the input into an executable resource, such as a library, configuration file, or template.

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
Read Files or Directories; Read Application Data	Scope: Confidentiality The injected code could access restricted data / files.
Bypass Protection Mechanism	Scope: Access Control In some cases, injectable code controls authentication; this may lead to a remote vulnerability.
Gain Privileges or Assume Identity	Scope: Access Control Injected code can access resources that the attacker is directly prevented from accessing.
Execute Unauthorized Code or Commands	Scope: Integrity, Confidentiality, Availability, Other Code injection attacks can lead to loss of data integrity in nearly all cases as the control-plane data injected is always incidental to data recall or writing. Additionally, code injection can often result in the execution of arbitrary code.
Hide Activities	Scope: Non-Repudiation Often the actions performed by injected control code are unlogged.

Potential Mitigations

Phase(s)	Mitigation
Implementation	Strategy: Input Validation Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
Implementation	Strategy: Output Encoding Perform proper output validation and escaping to neutralize all code syntax from data written to code files.

Phase(s)

Mitigation

Implementation

Strategy: Input Validation

Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.

When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."

Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

Implementation

Strategy: Output Encoding

Perform proper output validation and escaping to neutralize all code syntax from data written to code files.

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	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.	94	Improper Control of Generation of Code ('Code Injection')
ParentOf	Variant Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	97	Improper Neutralization of Server-Side Includes (SSI) Within a Web Page

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.	1019	Validate Inputs

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
Implementation	REALIZATION: This weakness is caused during implementation of an architectural security tactic.
Implementation	This issue is frequently found in PHP applications that allow users to set configuration variables that are stored within executable PHP files. Technically, this could also be performed in some compiled code (e.g., by byte-patching an executable), although it is highly unlikely.

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

PHP (Undetermined Prevalence)

Perl (Undetermined Prevalence)

Class: Interpreted (Undetermined Prevalence)

Demonstrative Examples

Example 1

This example attempts to write user messages to a message file and allow users to view them.

(bad code)

Example Language: PHP

$MessageFile = "messages.out";
if ($_GET["action"] == "NewMessage") {

$name = $_GET["name"];
$message = $_GET["message"];
$handle = fopen($MessageFile, "a+");
fwrite($handle, "<b>$name</b> says '$message'<hr>\n");
fclose($handle);
echo "Message Saved!<p>\n";

}
else if ($_GET["action"] == "ViewMessages") {

include($MessageFile);

}

While the programmer intends for the MessageFile to only include data, an attacker can provide a message such as:

(attack code)

name=h4x0r
message=%3C?php%20system(%22/bin/ls%20-l%22);?%3E

which will decode to the following:

(attack code)

<?php system("/bin/ls -l");?>

The programmer thought they were just including the contents of a regular data file, but PHP parsed it and executed the code. Now, this code is executed any time people view messages.

Notice that XSS (CWE-79) is also possible in this situation.

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
CVE-2002-0495	Perl code directly injected into CGI library file from parameters to another CGI program.
CVE-2005-1876	Direct PHP code injection into supporting template file.
CVE-2005-1894	Direct code injection into PHP script that can be accessed by attacker.
CVE-2003-0395	PHP code from User-Agent HTTP header directly inserted into log file implemented as PHP script.
CVE-2007-6652	chain: execution after redirect allows non-administrator to perform static code injection.

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)

Affected Resources

File or Directory

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	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.	990	SFP Secondary Cluster: Tainted Input to Command
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	1347	OWASP Top Ten 2021 Category A03:2021 - Injection
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	1409	Comprehensive Categorization: Injection

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.

Notes

Relationship

"HTML injection" (see CWE-79: XSS) could be thought of as an example of this, but the code is injected and executed on the client side, not the server side. Server-Side Includes (SSI) are an example of direct static code injection.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
PLOVER	Direct Static Code Injection
Software Fault Patterns	SFP24	Tainted Input to Command

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-35	Leverage Executable Code in Non-Executable Files
CAPEC-73	User-Controlled Filename
CAPEC-77	Manipulating User-Controlled Variables
CAPEC-81	Web Server Logs Tampering
CAPEC-85	AJAX Footprinting

Content History

Submissions
Submission Date	Submitter	Organization
2006年07月19日 (CWE Draft 3, 2006年07月19日)	PLOVER
2006年07月19日 (CWE Draft 3, 2006年07月19日)
Modifications
Modification Date	Modifier	Organization
2023年06月29日	CWE Content Team	MITRE
2023年06月29日	updated Mapping_Notes
2023年04月27日	CWE Content Team	MITRE
2023年04月27日	updated Modes_of_Introduction, Relationships, Time_of_Introduction
2023年01月31日	CWE Content Team	MITRE
2023年01月31日	updated Description
2022年10月13日	CWE Content Team	MITRE
2022年10月13日	updated Relationships, Taxonomy_Mappings
2021年10月28日	CWE Content Team	MITRE
2021年10月28日	updated Relationships
2021年03月15日	CWE Content Team	MITRE
2021年03月15日	updated Demonstrative_Examples
2020年06月25日	CWE Content Team	MITRE
2020年06月25日	updated Potential_Mitigations
2020年02月24日	CWE Content Team	MITRE
2020年02月24日	updated Potential_Mitigations, Relationships, Taxonomy_Mappings
2017年11月08日	CWE Content Team	MITRE
2017年11月08日	updated Affected_Resources, Applicable_Platforms, Causal_Nature, Demonstrative_Examples, Enabling_Factors_for_Exploitation, Modes_of_Introduction, Relationships
2017年05月03日	CWE Content Team	MITRE
2017年05月03日	updated Related_Attack_Patterns
2014年07月30日	CWE Content Team	MITRE
2014年07月30日	updated Relationships, Taxonomy_Mappings
2014年06月23日	CWE Content Team	MITRE
2014年06月23日	updated Enabling_Factors_for_Exploitation, Other_Notes, Relationship_Notes
2013年02月21日	CWE Content Team	MITRE
2013年02月21日	updated Observed_Examples
2012年10月30日	CWE Content Team	MITRE
2012年10月30日	updated Potential_Mitigations
2012年05月11日	CWE Content Team	MITRE
2012年05月11日	updated Common_Consequences, Demonstrative_Examples, Relationships
2011年06月01日	CWE Content Team	MITRE
2011年06月01日	updated Common_Consequences
2010年06月21日	CWE Content Team	MITRE
2010年06月21日	updated Potential_Mitigations
2010年04月05日	CWE Content Team	MITRE
2010年04月05日	updated Description, Name
2009年05月27日	CWE Content Team	MITRE
2009年05月27日	updated Description, Name
2008年09月08日	CWE Content Team	MITRE
2008年09月08日	updated Applicable_Platforms, Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities
2008年07月01日	Eric Dalci	Cigital
2008年07月01日	updated Potential_Mitigations, Time_of_Introduction
Previous Entry Names
Change Date	Previous Entry Name
2008年04月11日	Direct Static Code Injection
2009年05月27日	Insufficient Control of Directives in Statically Saved Code (Static Code Injection)
2010年04月05日	Improper Sanitization of Directives in Statically Saved Code ('Static Code Injection')

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Page Last Updated: September 09, 2025

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