CVE-2012-5481 in Moodle
Summary
by MITRE
Moodle 2.3.x before 2.3.3 allows remote authenticated users to bypass the moodle/role:manage capability requirement and read all capability data by visiting the Check Permissions page.
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Analysis
by VulDB Data Team • 02/24/2019
The vulnerability identified as CVE-2012-5481 affects Moodle version 2.3.x prior to 2.3.3 and represents a critical access control flaw that undermines the platform's security model. This issue resides within the role management functionality of Moodle, specifically in how the system validates permissions when accessing the Check Permissions page. The vulnerability allows authenticated users to bypass intended capability restrictions, creating an unauthorized access vector that could lead to information disclosure and privilege escalation. The flaw demonstrates a failure in the authorization mechanism that should prevent users from viewing capability data beyond their assigned permissions.
The technical implementation of this vulnerability stems from inadequate input validation and permission checking within the role management module. When users navigate to the Check Permissions page, the system fails to properly verify whether the authenticated user possesses the required moodle/role:manage capability before displaying sensitive capability information. This represents a classic authorization bypass vulnerability where the system assumes that authenticated users should have access to certain administrative functions without proper capability verification. The flaw aligns with CWE-285, which addresses improper authorization in software systems, and specifically manifests as a weakness in access control validation.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to gather comprehensive data about the system's capability structure and user permissions. An authenticated user could potentially map out the entire permission landscape of a Moodle installation, identifying administrative capabilities and understanding how roles are assigned throughout the platform. This intelligence gathering capability could serve as a foundation for more sophisticated attacks, including privilege escalation attempts or targeted exploitation of other system components. The vulnerability directly violates the principle of least privilege and could enable attackers to craft more effective attack vectors against the platform.
Organizations utilizing affected Moodle versions should prioritize immediate remediation through the application of the official security patch released for version 2.3.3. The patch addresses the core authorization bypass issue by implementing proper capability validation before displaying capability data on the Check Permissions page. Additionally, system administrators should conduct comprehensive security audits to verify that no unauthorized access has occurred and review user permissions to ensure proper segregation of duties. Implementing network segmentation and monitoring for suspicious access patterns to administrative pages can provide additional defensive layers. This vulnerability demonstrates the importance of regular security updates and proper access control implementation in educational platforms, as highlighted by ATT&CK technique T1078 which covers valid accounts and privilege escalation through unauthorized access to administrative functions.