CVE-2012-1582 in MediaWiki
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the wikitext parser in MediaWiki 1.17.x before 1.17.3 and 1.18.x before 1.18.2 allows remote attackers to inject arbitrary web script or HTML via a crafted page with "forged strip item markers," as demonstrated using the CharInsert extension.
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Analysis
by VulDB Data Team • 03/22/2021
The vulnerability described in CVE-2012-1582 represents a critical cross-site scripting flaw within MediaWiki's wikitext parser implementation. This security weakness affected versions 1.17.x prior to 1.17.3 and 1.18.x prior to 1.18.2, creating a significant attack surface for remote threat actors seeking to exploit web applications built on this platform. The vulnerability specifically targeted the parser's handling of strip item markers, which are used to process and format content within wiki environments where users can create and edit pages through a markup language interface.
The technical exploitation mechanism involves crafting malicious wiki pages that contain forged strip item markers designed to bypass the parser's input validation mechanisms. When the MediaWiki wikitext parser processes these specially crafted pages, it fails to properly sanitize the input, allowing attacker-controlled script code to be embedded within the page content. The CharInsert extension served as a demonstration vector for this attack, showing how legitimate extensions could become conduits for XSS payloads when combined with the parser vulnerability. This particular flaw demonstrates a weakness in the parser's ability to distinguish between legitimate markup elements and potentially malicious code sequences.
The operational impact of this vulnerability extends beyond simple script injection, as it enables attackers to execute arbitrary web scripts in the context of users' browsers who view affected wiki pages. This capability allows for session hijacking, credential theft, data exfiltration, and the potential for further exploitation through browser-based attacks. The vulnerability affects not only individual users but also entire wiki communities since malicious content can be introduced through any page that accepts user-generated content. Organizations relying on MediaWiki for collaborative documentation, knowledge management, or internal wikis face significant risks when operating vulnerable versions, as the attack surface includes any user with editing privileges who might inadvertently or maliciously introduce the forged markers.
Mitigation strategies for this vulnerability require immediate patching of affected MediaWiki installations to versions 1.17.3 or 1.18.2, which contain the necessary parser fixes. Organizations should also implement additional defensive measures including input validation at multiple levels, content security policy enforcement, and regular security audits of extensions and custom modifications. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications, and represents a typical example of how parser vulnerabilities can be exploited through markup language injection techniques. From an ATT&CK framework perspective, this vulnerability maps to T1566, representing the initial access phase through malicious content, and T1059, representing the execution of code through web-based attack vectors. Regular security monitoring and user education regarding the risks of editing content from untrusted sources remain essential components of comprehensive defense strategies against such exploitation techniques.