Détail du CWE-98

The PHP application receives input from an upstream component, but it does not restrict or incorrectly restricts the input before its usage in "require," "include," or similar functions.

In certain versions and configurations of PHP, this can allow an attacker to specify a URL to a remote location from which the product will obtain the code to execute. In other cases in association with path traversal, the attacker can specify a local file that may contain executable statements that can be parsed by PHP.

Modes d'introduction

Implementation : REALIZATION: This weakness is caused during implementation of an architectural security tactic.

Plateformes applicables

Langue

Name: PHP (Often)

Technologies

Class: Web Based (Undetermined)
Name: Web Server (Undetermined)

Conséquences courantes

Exemples observés

Mesures d’atténuation potentielles

Phases : Architecture and Design
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].
Phases : Architecture and Design
Phases : Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Phases : Architecture and Design // Operation
Phases : Architecture and Design // Operation
Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
Phases : Implementation
Phases : Architecture and Design // Operation
Phases : Architecture and Design // Implementation
Phases : Operation
Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
Phases : Operation // Implementation
Develop and run your code in the most recent versions of PHP available, preferably PHP 6 or later. Many of the highly risky features in earlier PHP interpreters have been removed, restricted, or disabled by default.
Phases : Operation // Implementation
Phases : Operation
Set allow_url_fopen to false, which limits the ability to include files from remote locations.

Méthodes de détection

Manual Analysis

Manual white-box analysis can be very effective for finding this issue, since there is typically a relatively small number of include or require statements in each program.
Efficacité : High

Automated Static Analysis

Notes de cartographie des vulnérabilités

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

Modèles d'attaque associés

Notes

Références

REF-185

Testing for Path Traversal (OWASP-AZ-001)
OWASP.
http://www.owasp.org/index.php/Testing_for_Path_Traversal_(OWASP-AZ-001)

REF-76

Least Privilege
Sean Barnum, Michael Gegick.
https://web.archive.org/web/20211209014121/https://www.cisa.gov/uscert/bsi/articles/knowledge/principles/least-privilege

REF-951

A Study in Scarlet
Shaun Clowes.
https://www.cgisecurity.com/lib/studyinscarlet.txt

REF-952

Suhosin
Stefan Esser.
http://www.hardened-php.net/suhosin/

REF-953

Top 25 Series - Rank 13 - PHP File Inclusion
Johannes Ullrich.
https://www.sans.org/blog/top-25-series-rank-13-php-file-inclusion/

REF-1481

D3FEND: Application Layer Firewall
D3FEND.
https://d3fend.mitre.org/dao/artifact/d3f:ApplicationLayerFirewall/

REF-1482

D3FEND: D3-TL Trusted Library
D3FEND.
https://d3fend.mitre.org/technique/d3f:TrustedLibrary/

Soumission

Modifications