CVE-2012-2359 in Moodle
Summary
by MITRE
admin/roles/override.php in Moodle 2.0.x before 2.0.9, 2.1.x before 2.1.6, and 2.2.x before 2.2.3 allows remote authenticated users to gain privileges by leveraging the teacher role and modifying their own capabilities, as demonstrated by obtaining the backup:userinfo capability.
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Analysis
by VulDB Data Team • 12/06/2021
The vulnerability described in CVE-2012-2359 represents a critical privilege escalation flaw within the Moodle learning management system that affects multiple version branches including 2.0.x through 2.0.8, 2.1.x through 2.1.5, and 2.2.x through 2.2.2. This issue resides in the administrative roles override functionality located at admin/roles/override.php, where authenticated users with the teacher role can manipulate their own capabilities to gain unauthorized access to additional system privileges. The vulnerability specifically allows attackers to obtain the backup:userinfo capability, which enables them to access sensitive user information during backup operations, thereby undermining the security model of the platform.
The technical flaw stems from inadequate access controls and capability validation within the role override mechanism of Moodle's permission system. When teachers attempt to modify their own capabilities through the override interface, the system fails to properly validate whether the requested capability changes are appropriate for the user's current role or if they would grant excessive privileges. This represents a classic case of insufficient authorization checks and privilege management flaws that align with CWE-285, which addresses insufficient authorization issues in software systems. The vulnerability operates through a capability manipulation attack vector where authenticated users can exploit the role override functionality to expand their privileges beyond what should be permitted for their assigned teacher role.
The operational impact of this vulnerability is significant as it allows authenticated attackers with teacher-level access to escalate their privileges and access sensitive user data. The backup:userinfo capability specifically enables attackers to extract user information during backup operations, potentially exposing personal data, login credentials, or other confidential information. This compromise can lead to data breaches, unauthorized access to student records, and potential further exploitation within the learning management system. The vulnerability affects the core integrity of Moodle's role-based access control model and undermines the trust model that educational institutions rely upon for protecting student data and maintaining privacy standards. According to ATT&CK framework, this vulnerability maps to privilege escalation techniques and credential access categories, specifically targeting the T1078 and T1566 tactics that involve unauthorized access and credential theft.
Organizations utilizing affected Moodle versions should immediately implement mitigations including applying the official patches released by Moodle for versions 2.0.9, 2.1.6, and 2.2.3 respectively. System administrators should also review and tighten role assignments to ensure that teacher accounts have minimal necessary capabilities and that the role override functionality is properly monitored. Additional defensive measures include implementing network segmentation to limit access to administrative interfaces and conducting regular security audits of user capabilities and role assignments. The vulnerability highlights the importance of proper capability management and access control validation in educational platforms where sensitive user data is processed and stored, emphasizing the need for comprehensive security testing and regular vulnerability assessments.