CVE-2012-2354 in Moodle
Summary
by MITRE
Moodle 2.1.x before 2.1.6 and 2.2.x before 2.2.3 allows remote authenticated users to bypass the moodle/site:readallmessages capability requirement and read arbitrary messages by using the "Recent conversations" feature with a modified parameter in a URL.
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Analysis
by VulDB Data Team • 12/06/2021
The vulnerability identified as CVE-2012-2354 represents a critical access control flaw in Moodle learning management systems version 2.1.x prior to 2.1.6 and 2.2.x prior to 2.2.3. This issue stems from insufficient input validation and parameter manipulation within the messaging system, specifically affecting the "Recent conversations" feature that users employ to access their message history. The vulnerability allows authenticated users to bypass intended security controls by crafting malicious URLs with modified parameters, thereby gaining unauthorized access to messages that should be restricted to specific users or roles.
The technical implementation of this vulnerability resides in the way Moodle processes URL parameters for the recent conversations functionality. When users navigate to the recent conversations page, the system relies on specific parameter values to determine which messages to display and who can access them. Attackers can manipulate these parameters to view messages belonging to other users, effectively circumventing the moodlesitereadallmessages capability requirement that should normally restrict such access. This flaw operates at the application logic level and demonstrates poor input sanitization practices, where the system fails to properly validate user-supplied parameters before executing access control checks.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables unauthorized users to access potentially sensitive communications between students, instructors, and administrators. This could include personal information, academic records, confidential discussions, or any other content that users expect to remain private within the learning environment. The vulnerability affects the integrity of the system's access control model and could potentially be exploited as part of broader attacks targeting user privacy, academic integrity, or institutional data protection. Security researchers have classified this as a privilege escalation vulnerability that undermines the core security assumptions of the messaging system.
Organizations using affected Moodle versions should immediately apply the security patches released by Moodle developers to address this vulnerability. The mitigation strategy involves updating to Moodle 2.1.6 or 2.2.3 and ensuring that all users are properly authenticated before accessing messaging features. System administrators should also implement additional monitoring to detect unusual access patterns in the messaging system and consider implementing network-level controls to restrict access to sensitive functionality. This vulnerability aligns with CWE-284, which addresses improper access control, and could be leveraged as part of broader attack chains in the MITRE ATT&CK framework under the privilege escalation and defense evasion tactics. The incident underscores the importance of proper input validation and capability-based access controls in web applications, particularly those handling sensitive educational data.