CVE-2013-2079 in Moodle
Summary
by MITRE
mod/assign/locallib.php in the assignment module in Moodle 2.3.x before 2.3.7 and 2.4.x before 2.4.4 does not consider capability requirements during the processing of ZIP assignment-archive download (aka downloadall) requests, which allows remote authenticated users to read other users assignments by leveraging the student role.
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Analysis
by VulDB Data Team • 01/02/2022
The vulnerability identified as CVE-2013-2079 resides within the assignment module of Moodle learning management system, specifically in the mod/assign/locallib.php file. This flaw affects versions 2.3.x prior to 2.3.7 and 2.4.x prior to 2.4.4, representing a critical security oversight that undermines the platform's access control mechanisms. The vulnerability manifests during the processing of ZIP assignment-archive download requests, commonly referred to as downloadall functionality, which is designed to aggregate and provide students with downloadable archives of their assignment submissions.
The technical flaw stems from the absence of proper capability checks within the assignment module's processing logic. When authenticated users request the downloadall functionality, the system fails to verify whether the requesting user possesses the appropriate permissions to access the assignment submissions of other users. This capability bypass occurs because the code does not validate the user's role and permissions before aggregating and serving the archive files. The vulnerability specifically leverages the student role, meaning that authenticated users with student privileges can exploit this weakness to gain unauthorized access to assignments submitted by other students within the same course or context.
The operational impact of this vulnerability is significant as it enables remote authenticated attackers to perform unauthorized data access and potential information disclosure. An attacker with a valid student account can systematically download ZIP archives containing assignments from other students, potentially exposing sensitive academic work, personal information, or intellectual property. This breach of privacy and data integrity represents a serious compromise of the educational platform's security model, as it undermines the fundamental principle of user isolation and access control that Moodle's role-based access control system is designed to enforce.
The vulnerability aligns with CWE-284, which describes improper access control scenarios where insufficient checks are performed to ensure that users have appropriate permissions before accessing resources. This weakness enables privilege escalation and unauthorized data access, directly violating the principle of least privilege that should govern all system interactions. From an ATT&CK framework perspective, this vulnerability maps to T1078, which covers valid accounts and T1566, which covers credential harvesting, as it allows unauthorized access to student data through legitimate user accounts.
Mitigation strategies for this vulnerability involve implementing proper capability checks within the assignment module's downloadall functionality. System administrators should immediately upgrade to patched versions of Moodle 2.3.7 or 2.4.4, as these releases contain the necessary security fixes. Additionally, organizations should review and enforce proper role assignments, ensuring that users only possess the minimum required capabilities for their legitimate purposes. Network-level monitoring should be implemented to detect unusual download patterns that might indicate exploitation attempts, and regular security audits should verify that access controls remain properly configured. The fix typically involves adding capability checks that validate whether the requesting user has the appropriate permissions to access the specific assignment submissions being requested, thereby preventing unauthorized data access through the downloadall functionality.