CVE-2006-0322 in MediaWiki
Summary
by MITRE
Unspecified vulnerability the edit comment formatting functionality in MediaWiki 1.5.x before 1.5.6 and 1.4.x before 1.4.14 allows attackers to cause a denial of service (infinite loop) via "certain malformed links."
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Analysis
by VulDB Data Team • 06/08/2017
The vulnerability identified as CVE-2006-0322 represents a critical denial of service weakness within MediaWiki's comment formatting functionality. This issue affects versions 1.5.x prior to 1.5.6 and 1.4.x prior to 1.4.14, exposing systems to potential disruption through specifically crafted malformed links. The flaw manifests as an infinite loop condition that can be triggered during the processing of user-generated content, particularly when comments contain carefully constructed link structures that exploit parsing routines within the wiki software.
The technical implementation of this vulnerability stems from inadequate input validation and error handling within MediaWiki's link parsing algorithms. When the system encounters certain malformed links within comment text, the formatting engine enters a recursive processing loop that fails to terminate properly. This behavior aligns with CWE-835, which describes infinite loops or iterations that lack proper termination conditions. The flaw demonstrates how seemingly benign user input can be weaponized to consume system resources and render the application unresponsive.
Operational impact of this vulnerability extends beyond simple service disruption to potentially affect entire wiki installations and their associated communities. An attacker could exploit this weakness by submitting comments containing maliciously constructed links that trigger the infinite loop, causing the web server to consume excessive CPU cycles and memory resources. This resource exhaustion could lead to complete service unavailability, affecting legitimate users who attempt to access or contribute to the wiki content. The vulnerability particularly impacts collaborative environments where user-generated content is prevalent, making it a significant concern for organizations relying on MediaWiki for documentation and knowledge sharing.
Mitigation strategies for this vulnerability involve applying the official patches released by MediaWiki developers, specifically upgrading to versions 1.5.6 or 1.4.14 and later. System administrators should implement input sanitization measures that validate and normalize all user-generated content before processing, particularly focusing on link structures and formatting elements. Network-level protections such as rate limiting and resource monitoring can help detect and prevent exploitation attempts. Additionally, organizations should consider implementing web application firewalls that can identify and block suspicious link patterns. The remediation process should include comprehensive testing to ensure that the patch does not introduce regressions in legitimate functionality while maintaining the system's ability to properly handle valid user input. This vulnerability exemplifies the importance of robust input validation and proper error handling in web applications, as outlined in various security frameworks including the OWASP Top Ten and NIST cybersecurity guidelines.