CVE-2014-2242 in MediaWiki
Summary
by MITRE
includes/upload/UploadBase.php in MediaWiki before 1.19.12, 1.20.x and 1.21.x before 1.21.6, and 1.22.x before 1.22.3 does not prevent use of invalid namespaces in SVG files, which allows remote attackers to conduct cross-site scripting (XSS) attacks via an SVG upload, as demonstrated by use of a W3C XHTML namespace in conjunction with an IFRAME element.
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Analysis
by VulDB Data Team • 04/12/2025
The vulnerability described in CVE-2014-2242 represents a critical cross-site scripting flaw in MediaWiki's SVG upload handling mechanism. This issue affects multiple versions of the popular wiki software including 1.19.12, 1.20.x, 1.21.x, and 1.22.x releases prior to their respective security patches. The vulnerability stems from insufficient validation of namespace declarations within SVG files, specifically failing to properly sanitize or reject invalid namespaces that could be leveraged for malicious purposes.
The technical flaw occurs within the UploadBase.php file located in MediaWiki's includes/upload directory. This component is responsible for processing file uploads and performs validation on uploaded content before allowing it to be stored and potentially displayed to users. The vulnerability arises because the system does not adequately filter or reject SVG files containing invalid namespace declarations, particularly those that include the W3C XHTML namespace. When an attacker uploads a specially crafted SVG file that incorporates both the XHTML namespace and an IFRAME element, the system fails to properly validate these elements, allowing the malicious code to persist in the uploaded file.
The operational impact of this vulnerability is significant as it enables remote attackers to conduct cross-site scripting attacks through the SVG upload functionality. Attackers can exploit this flaw by creating malicious SVG files that contain embedded IFRAME elements with malicious payloads, potentially redirecting users to phishing sites or executing arbitrary JavaScript code within the context of other users' browsers. This type of vulnerability can be particularly dangerous in collaborative environments where users may trust content uploaded by others, as the malicious code could be executed whenever the compromised SVG file is viewed or processed by the wiki application.
The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications, and demonstrates how improper input validation can lead to severe security implications. From an ATT&CK perspective, this vulnerability maps to T1566, specifically the technique of "Phishing with Malicious File", as attackers can use the upload functionality to deliver malicious files that trigger XSS attacks. The flaw also relates to T1190, "Exploit Public-Facing Application", as it represents an attack vector that leverages publicly accessible upload mechanisms within the web application.
Organizations using affected versions of MediaWiki should immediately implement mitigations including upgrading to patched versions of the software, implementing additional input validation measures for SVG uploads, and potentially disabling SVG upload functionality until proper security measures can be implemented. The recommended approach involves applying the security patches released by the MediaWiki development team, which address the namespace validation issues in UploadBase.php. Additionally, administrators should consider implementing more comprehensive file type validation, content security policies, and regular security audits of upload mechanisms to prevent similar vulnerabilities from emerging in the future.