CVE-2014-7833 in Moodle
Summary
by MITRE
mod/data/edit.php in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 sets a certain group ID to zero upon a database-entry change, which allows remote authenticated users to obtain sensitive information by accessing the database after an edit by a teacher.
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Analysis
by VulDB Data Team • 04/04/2022
The vulnerability identified as CVE-2014-7833 resides within the Moodle learning management system's data editing functionality, specifically in the mod/data/edit.php component. This issue affects multiple versions of Moodle including 2.4.11 and earlier, 2.5.x versions before 2.5.9, 2.6.x versions before 2.6.6, and 2.7.x versions before 2.7.3. The flaw represents a critical security weakness that undermines the integrity of user access controls and data protection mechanisms within the platform. The vulnerability manifests when a teacher performs an edit operation on database entries, creating a scenario where sensitive information can be accessed by unauthorized users who should not have such privileges.
The technical implementation of this vulnerability stems from improper handling of group identifiers during database modification operations. When a teacher modifies data entries within the Moodle environment, the system fails to maintain proper group ID associations in the database records. This malfunction causes certain group identifiers to be reset to zero values, effectively removing access restrictions that should normally prevent unauthorized users from viewing specific data sets. The flaw operates at the database level where group membership permissions are not properly preserved during update operations, creating a persistent security gap that can be exploited by authenticated users with lower privileges.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally compromises the security model of Moodle's data management system. An attacker with teacher-level access can manipulate database records in such a way that sensitive information becomes accessible to other users who should not be able to view it. This represents a significant breach of the principle of least privilege and can lead to unauthorized access to student information, assignment data, and other confidential educational materials. The vulnerability's persistence means that once exploited, the compromised data access permissions remain active until the system is properly patched or the database is manually corrected.
From a cybersecurity perspective, this vulnerability aligns with CWE-200, which addresses "Information Exposure," and demonstrates characteristics consistent with privilege escalation attacks. The flaw enables unauthorized information access through legitimate system operations, making it particularly dangerous as it exploits normal user workflows rather than requiring unusual attack vectors. The ATT&CK framework categorizes this issue under privilege escalation and defense evasion techniques, as it allows attackers to bypass intended access controls and maintain persistent access to sensitive data. Organizations using affected Moodle versions face potential compliance violations and data breach risks, particularly in educational environments where student privacy is paramount.
The recommended mitigation strategy involves applying the official patches released by Moodle for the affected versions, which address the improper group ID handling during database updates. System administrators should immediately upgrade to patched versions of Moodle and conduct thorough security audits of their database configurations. Additionally, implementing proper access control monitoring and regular security assessments can help detect and prevent exploitation attempts. Organizations should also consider implementing database activity logging and alerting mechanisms to monitor for unusual data access patterns that might indicate exploitation of this vulnerability. The vulnerability serves as a reminder of the critical importance of proper input validation and access control implementation in web-based educational platforms.