CVE-2014-9507 in MediaWiki
Summary
by MITRE
MediaWiki 1.21.x, 1.22.x before 1.22.14, and 1.23.x before 1.23.7, when $wgContentHandlerUseDB is enabled, allows remote attackers to conduct cross-site scripting (XSS) attacks by setting the content model for a revision to JS.
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Analysis
by VulDB Data Team • 03/09/2019
MediaWiki version 1.21.x through 1.22.x before 1.22.14 and 1.23.x before 1.23.7 contains a cross-site scripting vulnerability that arises when the $wgContentHandlerUseDB configuration parameter is enabled. This flaw enables remote attackers to inject malicious JavaScript code through manipulation of revision content models, specifically targeting the JavaScript content model. The vulnerability stems from insufficient input validation and sanitization mechanisms within the content handling system that fails to properly escape or filter user-supplied content before rendering it in web pages. When $wgContentHandlerUseDB is enabled, MediaWiki stores content model information in the database and retrieves it during page rendering, creating an attack surface where maliciously crafted content models can be executed in the context of authenticated user sessions. The vulnerability is classified under CWE-79 as improper neutralization of input during web page generation, which represents a fundamental weakness in web application security. This issue directly maps to attack techniques described in the MITRE ATT&CK framework under T1059.007 for JavaScript execution and T1566 for credential harvesting through web-based attacks.
The technical exploitation of this vulnerability occurs when an attacker modifies a page revision to use the JavaScript content model, allowing them to inject malicious scripts that execute in the browser context of other users who view the affected page. The flaw is particularly dangerous because it leverages legitimate MediaWiki functionality for content handling while bypassing normal security controls. When users access pages containing malicious JavaScript content, the script executes with the privileges of the victim user, potentially enabling session hijacking, data theft, or further compromise of the affected system. The vulnerability is exacerbated by the fact that it requires minimal user interaction beyond viewing a page, making it particularly effective for mass distribution attacks. The security implications extend beyond simple XSS as the attacker can potentially access cookies, local storage, and other session data that may contain sensitive information.
The operational impact of this vulnerability is significant for MediaWiki installations that have enabled the $wgContentHandlerUseDB option, as it creates a persistent threat vector that can be exploited by attackers with minimal technical skill. Organizations using affected MediaWiki versions face risks including unauthorized data access, privilege escalation, and potential full system compromise if attackers can leverage the XSS to access administrative functions. The vulnerability affects not only individual user sessions but also enterprise installations where MediaWiki serves as a collaborative platform for sensitive information sharing. Security teams must consider the potential for this vulnerability to be used as a stepping stone for more sophisticated attacks, including credential theft and lateral movement within network environments. The impact is particularly severe in environments where MediaWiki is used for internal documentation, knowledge bases, or collaborative development platforms where users may have elevated privileges.
The recommended mitigation strategy involves immediate patching of affected MediaWiki versions to the latest stable releases that contain the XSS protection fixes. Organizations should disable the $wgContentHandlerUseDB configuration parameter if it is not essential for their deployment, as this removes the attack vector entirely. Additionally, implementing proper input validation and output encoding mechanisms can provide defense-in-depth protection against similar vulnerabilities. Security monitoring should include detection of unauthorized content model changes and suspicious revision modifications that may indicate exploitation attempts. Network-based intrusion detection systems should be configured to monitor for known malicious JavaScript patterns in HTTP traffic to affected MediaWiki installations. Regular security audits of MediaWiki configurations are essential to ensure that security-relevant parameters are properly set and that access controls remain effective against unauthorized modifications. Organizations should also consider implementing content security policies and web application firewalls to provide additional protection layers against exploitation attempts.