CVE-2018-10890 in Moodle
Summary
by MITRE
A flaw was found in moodle before versions 3.5.1, 3.4.4, 3.3.7, 3.1.13. It was possible for the core_course_get_categories web service to return hidden categories, which should be omitted when fetching course categories.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/06/2023
This vulnerability exists in the moodle learning management system where the core_course_get_categories web service fails to properly filter hidden course categories during data retrieval operations. The flaw affects versions prior to 3.5.1, 3.4.4, 3.3.7, and 3.1.13, representing a significant security oversight in the platform's access control mechanisms. The vulnerability is categorized under CWE-200, Information Exposure, as it allows unauthorized disclosure of information that should remain hidden from users. This represents a classic privilege escalation issue where users can access restricted data through improperly validated web service endpoints.
The technical implementation flaw stems from inadequate input validation and access control checks within the web service layer. When the core_course_get_categories function processes requests, it fails to properly verify whether the requesting user has appropriate permissions to view hidden categories. This oversight allows malicious actors or even legitimate users with elevated privileges to bypass the intended access controls. The vulnerability operates at the application layer and can be exploited through the web service API without requiring authentication credentials beyond what is already available to the user. According to ATT&CK framework, this maps to T1068, Valid Accounts, and T1213, Data from Information Repositories, as it enables unauthorized data access through legitimate service interfaces.
The operational impact of this vulnerability is substantial as it compromises the integrity of the course catalog structure and potentially exposes sensitive academic information. Hidden categories may contain information about restricted courses, private programs, or administrative data that should not be visible to general users. This exposure could lead to information disclosure, potentially affecting student privacy, course scheduling conflicts, or unauthorized access to restricted academic content. The vulnerability affects organizations using moodle for educational management, particularly those with complex course structures and multiple user roles where access control is paramount.
Organizations should immediately upgrade to the patched versions of moodle to resolve this vulnerability. System administrators should also implement additional monitoring of web service access patterns to detect potential exploitation attempts. The mitigation strategy includes not only the mandatory software upgrade but also the implementation of network-level access controls and API rate limiting to reduce the attack surface. Security teams should conduct thorough audits of web service endpoints to identify similar access control flaws in other applications. Regular vulnerability assessments and penetration testing should be performed to ensure that similar issues do not exist in other components of the educational technology stack. The fix addresses the core issue by implementing proper access control checks within the web service layer, ensuring that hidden categories are properly filtered based on user permissions and role-based access controls.