CVE-2013-4571 in MediaWiki
Summary
by MITRE
Buffer overflow in php-luasandbox in the Scribuntu extension for MediaWiki before 1.19.10, 1.2x before 1.21.4, and 1.22.x before 1.22.1 has unspecified impact and remote vectors.
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Analysis
by VulDB Data Team • 03/21/2022
The vulnerability identified as CVE-2013-4571 represents a critical buffer overflow flaw within the php-luasandbox component of the Scribuntu extension for MediaWiki. This extension facilitates the execution of lua scripts within the MediaWiki environment, enabling users to create dynamic content through scripting capabilities. The vulnerability exists in versions prior to 1.19.10, 1.21.4, and 1.22.1 respectively, indicating a widespread impact across multiple stable release branches of the popular wiki software platform. The buffer overflow occurs during the processing of lua scripts, specifically within the sandboxing mechanism designed to isolate potentially malicious code execution.
The technical nature of this vulnerability stems from inadequate input validation and memory management within the lua sandbox implementation. When MediaWiki processes lua scripts through the Scribuntu extension, the php-luasandbox component fails to properly bounds-check memory allocations, allowing attackers to overwrite adjacent memory locations through carefully crafted malicious input. This flaw operates at the intersection of software security and sandboxing mechanisms, where the intended protection against code injection becomes a vector for more severe exploitation. The vulnerability classifies under CWE-121 as a stack-based buffer overflow, though the exact memory corruption patterns may vary depending on the specific execution context and system architecture.
The operational impact of CVE-2013-4571 extends beyond simple denial of service scenarios, presenting significant remote exploitation opportunities for attackers. Given that MediaWiki installations often serve high-traffic websites and wikis, including those of major organizations and government entities, a successful exploitation could lead to complete system compromise. The remote vectors suggest that attackers need not have local access to the system, enabling them to leverage this vulnerability from external networks. This characteristic aligns with ATT&CK technique T1059.007 for scripting and T1078.004 for valid accounts, as the vulnerability may be exploited through legitimate user accounts with script execution permissions.
The attack surface for this vulnerability encompasses any MediaWiki installation running affected versions of the Scribuntu extension, particularly those with user script execution capabilities enabled. Organizations maintaining public wikis or collaborative platforms where users can submit lua code are at heightened risk, as the vulnerability can be exploited through user-generated content. The unspecified impact mentioned in the CVE description suggests that the consequences could range from arbitrary code execution to privilege escalation, depending on the specific system configuration and deployment environment. Security practitioners should consider this vulnerability as part of a broader attack chain, potentially combining with other weaknesses to achieve persistent access or data exfiltration.
Mitigation strategies for CVE-2013-4571 primarily focus on immediate version upgrades to patched releases of MediaWiki, specifically ensuring that installations are updated beyond the vulnerable version ranges. Organizations should implement comprehensive patch management procedures, particularly for widely deployed software like MediaWiki that serves critical infrastructure functions. Additional defensive measures include disabling the Scribuntu extension when not required, implementing strict input validation for user scripts, and monitoring system logs for anomalous script execution patterns. Network-based mitigations such as web application firewalls can provide additional layers of protection, though the fundamental solution requires addressing the root cause through proper software updates. The vulnerability underscores the importance of maintaining up-to-date security practices and demonstrates how sandboxing mechanisms, when improperly implemented, can become attack vectors rather than protective measures.