CVE-2012-3397 in Moodle
Summary
by MITRE
lib/modinfolib.php in Moodle 2.0.x before 2.0.10, 2.1.x before 2.1.7, 2.2.x before 2.2.4, and 2.3.x before 2.3.1 does not check for a group-membership requirement when determining whether an activity is unavailable or hidden, which allows remote authenticated users to bypass intended access restrictions by selecting an activity that is configured for a group of other users.
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Analysis
by VulDB Data Team • 12/06/2021
The vulnerability described in CVE-2012-3397 affects Moodle learning management systems across multiple versions including 2.0.x before 2.0.10, 2.1.x before 2.1.7, 2.2.x before 2.2.4, and 2.3.x before 2.3.1. This security flaw resides within the modinfolib.php module which handles activity information and visibility logic. The core issue stems from inadequate group membership validation during activity availability checks, creating a significant access control bypass opportunity. The vulnerability specifically impacts the group membership requirement enforcement mechanism that should prevent users from accessing activities restricted to specific user groups.
The technical flaw manifests in the lib/modinfolib.php file where the system fails to properly verify whether an authenticated user belongs to the designated group for a particular activity before determining its availability. This oversight allows remote authenticated attackers to bypass intended access restrictions by simply selecting activities that are configured for groups containing other users. The vulnerability represents a classic access control weakness where the system assumes that if an activity is visible to a user, it should be accessible regardless of group membership requirements. This misconfiguration creates a path where users can access restricted course materials that should only be available to specific group members.
The operational impact of this vulnerability is substantial as it undermines the fundamental group-based access control mechanisms that Moodle employs to maintain course integrity and user privacy. An attacker with valid authentication credentials can exploit this flaw to access course content that was explicitly restricted to specific user groups, potentially exposing sensitive academic information, assignments, or discussion forums. The vulnerability affects both instructors and students who may be incorrectly granted access to materials intended for particular cohorts, creating potential data exposure risks and compromising the educational environment's security posture. This issue particularly impacts courses that utilize group mode settings to separate student populations or protect confidential information.
From a cybersecurity perspective, this vulnerability aligns with CWE-284, which addresses improper access control mechanisms, and represents a clear violation of the principle of least privilege. The flaw enables privilege escalation through unauthorized access to group-restricted content, potentially allowing attackers to gain insights into other users' activities or access sensitive course materials. The ATT&CK framework categorizes this as an access control bypass technique where adversaries leverage system configuration weaknesses to circumvent intended security restrictions. Organizations using affected Moodle versions face increased risk of information disclosure and potential academic integrity violations. The vulnerability demonstrates the critical importance of proper input validation and access control enforcement in web applications, particularly those handling educational content with varying user permissions and group memberships.
Mitigation strategies should prioritize immediate patching of affected Moodle installations to versions 2.0.10, 2.1.7, 2.2.4, and 2.3.1 respectively. Administrators should also conduct thorough audits of group-based access configurations to identify any potential exploitation that may have occurred. Additional defensive measures include implementing network-level access controls, monitoring for unusual activity patterns related to group membership changes, and ensuring that all users have appropriate access level permissions. Regular security assessments of learning management systems are essential to identify similar configuration weaknesses that could enable access control bypass scenarios. The vulnerability serves as a reminder of the critical need for proper access control validation in educational platforms where user privacy and academic integrity are paramount considerations.