CVE-2014-0122 in Moodle
Summary
by MITRE
mod/chat/chat_ajax.php in Moodle through 2.3.11, 2.4.x before 2.4.9, 2.5.x before 2.5.5, and 2.6.x before 2.6.2 does not properly check for the mod/chat:chat capability during chat sessions, which allows remote authenticated users to bypass intended access restrictions in opportunistic circumstances by remaining in a chat session after an intra-session capability removal by an administrator.
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Analysis
by VulDB Data Team • 05/08/2026
The vulnerability identified as CVE-2014-0122 affects the Moodle learning management system and represents a significant access control flaw that undermines the security model of chat functionality within the platform. This issue exists in multiple versions of Moodle including 2.3.11 and earlier, 2.4.x versions before 2.4.9, 2.5.x versions before 2.5.5, and 2.6.x versions before 2.6.2. The flaw specifically resides in the mod/chat/chat_ajax.php file which handles asynchronous chat operations. The vulnerability stems from improper capability checking mechanisms that fail to validate user permissions during active chat sessions.
The technical flaw manifests when an administrator removes chat capabilities from a user during an active chat session. Normally, such capability revocation should immediately terminate or restrict the user's access to chat functionality. However, the vulnerable code does not continuously validate these permissions, allowing previously authorized users to continue participating in chat sessions even after their access rights have been revoked. This creates a window of opportunity where malicious or compromised users can exploit this temporal inconsistency to maintain access to chat features they should no longer possess.
This vulnerability operates under the Common Weakness Enumeration framework as a weakness related to improper privilege management and access control enforcement. The issue directly maps to CWE-285, which addresses improper authorization in systems, and CWE-345, which covers insufficient checks for data integrity. The flaw also aligns with ATT&CK technique T1078.004 which covers valid accounts used for privilege escalation and persistence. The operational impact of this vulnerability extends beyond simple unauthorized access as it creates a persistent backdoor that can be exploited by attackers who gain legitimate access to the system.
The security implications of CVE-2014-0122 are particularly concerning because it allows for privilege escalation and potential information disclosure within educational environments. When an administrator removes chat access from a user, they expect that user to be completely restricted from chat communications. However, the vulnerability permits continued access, potentially allowing users to communicate with others, access chat history, or participate in discussions they should not be authorized to join. This can lead to unauthorized information sharing, disruption of educational activities, and potential exposure of sensitive academic content.
Organizations using affected Moodle versions should immediately implement mitigations including applying the official patches released by Moodle developers, which address the capability checking mechanism in the chat_ajax.php file. Administrators should also consider implementing additional monitoring controls to detect unusual chat activity patterns and establish more robust session management policies. The vulnerability demonstrates the importance of continuous access validation during active sessions rather than relying solely on initial capability checks. Security teams should also review their privilege management policies and ensure that chat access controls are properly enforced across all user sessions to prevent similar issues in other components of the system.