CVE-2017-2643 in Moodle
Summary
by MITRE
In Moodle 3.2.x, global search displays user names for unauthenticated users.
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Analysis
by VulDB Data Team • 11/15/2022
The vulnerability identified as CVE-2017-2643 resides within Moodle version 3.2.x and represents a significant information disclosure flaw that undermines the platform's authentication mechanisms. This issue manifests when the global search functionality is utilized by unauthenticated users, who are able to view user names and potentially other identifying information that should remain restricted to authenticated users. The flaw directly violates fundamental security principles by exposing user data without proper access controls, creating an avenue for unauthorized information gathering and potential reconnaissance activities.
The technical implementation of this vulnerability stems from improper access control validation within the global search module. When unauthenticated users access the search functionality, the system fails to properly verify user authentication status before displaying search results that include user names and related information. This represents a classic case of insufficient authorization checks, where the application does not adequately distinguish between authenticated and unauthenticated sessions when processing search queries. The vulnerability is particularly concerning because it operates at the application logic level rather than a network or system level, making it more difficult to detect and exploit through traditional network-based security measures.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates potential pathways for social engineering attacks and user enumeration. Attackers can systematically query the global search functionality to identify valid user accounts and potentially gather intelligence about the user base, which could facilitate targeted attacks such as credential stuffing or spear-phishing campaigns. The exposure of user names also violates privacy expectations and could compromise user anonymity within the learning management system environment. This vulnerability directly maps to CWE-284 Access Control Issues, specifically addressing inadequate access control validation mechanisms that allow unauthorized access to protected resources.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1087.001 Account Discovery - Local Account, as it enables attackers to enumerate user accounts through legitimate search functionality. The impact is particularly severe in educational environments where user privacy and data protection are paramount considerations. Organizations using Moodle 3.2.x are vulnerable to information disclosure attacks that could lead to targeted attacks against specific users, potentially exposing sensitive academic or personal information. The vulnerability affects the confidentiality aspect of the CIA triad by allowing unauthorized disclosure of user information.
The recommended mitigations for this vulnerability include immediate patching to the latest stable Moodle versions where the issue has been resolved through proper access control implementation. Organizations should also consider implementing additional security controls such as rate limiting on search functionality to prevent systematic enumeration attacks. Network-level protections including firewalls and intrusion detection systems can help monitor for unusual search patterns that might indicate exploitation attempts. Additionally, administrators should review and tighten access controls for search functionality, ensuring that user information is only accessible to authenticated users with appropriate permissions. Regular security audits and penetration testing should be conducted to identify similar access control issues within the Moodle environment and other applications. The vulnerability underscores the importance of comprehensive access control testing and validation in web applications, particularly those handling user data in educational and professional contexts.