CVE-2015-5265 in Moodle
Summary
by MITRE
The wiki component in Moodle through 2.6.11, 2.7.x before 2.7.10, 2.8.x before 2.8.8, and 2.9.x before 2.9.2 does not consider the mod/wiki:managefiles capability before authorizing file management, which allows remote authenticated users to delete arbitrary files by using a manage-files button in a text editor.
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Analysis
by VulDB Data Team • 07/08/2022
The vulnerability described in CVE-2015-5265 affects the wiki component within Moodle learning management systems across multiple version ranges including 2.6.11 and earlier, 2.7.x versions before 2.7.10, 2.8.x versions before 2.8.8, and 2.9.x versions before 2.9.2. This represents a critical authorization flaw that undermines the security model of the platform's file management capabilities. The vulnerability specifically targets the mod/wiki:managefiles capability which should normally control access to file management functions within wiki modules.
The technical flaw manifests when authenticated users exploit a weakness in the wiki component's permission checking mechanism. During text editing operations, users can access a manage-files button that should require the mod/wiki:managefiles capability to function properly. However, due to insufficient validation, this button operates without proper authorization checks, allowing malicious users to delete arbitrary files from the system. This occurs because the wiki component fails to verify whether the authenticated user possesses the necessary permissions before enabling file management functionality.
The operational impact of this vulnerability is severe and multifaceted. Remote authenticated users who can access the wiki component can leverage this flaw to delete critical system files, potentially causing system instability, data loss, or complete service disruption. The vulnerability enables attackers to target files beyond the intended scope of wiki operations, creating a pathway for broader system compromise. This issue particularly affects educational institutions and organizations relying on Moodle for their learning management needs, as it could lead to unauthorized modification or deletion of course materials, user data, or system configurations.
The vulnerability aligns with CWE-284, which describes improper access control in software systems, specifically targeting the failure to properly enforce authorization checks. From an attack perspective, this flaw maps to techniques in the ATT&CK framework under privilege escalation and persistence categories, as attackers can leverage the unauthorized file deletion capabilities to maintain access or cause further damage. Organizations should implement immediate mitigations including applying the relevant security patches released by Moodle, reviewing and tightening the mod/wiki:managefiles capability assignments, and monitoring user activities within wiki modules for suspicious file deletion patterns.
The security implications extend beyond simple file deletion to include potential data integrity violations and system availability threats. Attackers could strategically delete configuration files or critical database components, leading to complete system outages or data corruption. Additionally, the vulnerability demonstrates the importance of proper capability-based access controls in web applications, where insufficient validation of user permissions can create dangerous escalation paths. Organizations should also consider implementing additional monitoring controls specifically targeting wiki module file operations and establishing clear user permission policies that align with the principle of least privilege.