CVE-2025-3636 in Moodle
Summary
by MITRE • 04/25/2025
A flaw was found in Moodle. This vulnerability allows unauthorized users to access and view RSS feeds due to insufficient capability checks.
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Analysis
by VulDB Data Team • 06/24/2025
This vulnerability exists within the Moodle learning management system where inadequate authorization controls permit unauthorized users to access RSS feed content that should be restricted to authorized personnel only. The flaw represents a critical access control weakness that undermines the system's security model and could potentially expose sensitive educational content to individuals without proper credentials or permissions.
The technical implementation of this vulnerability stems from insufficient capability checks within the RSS feed access mechanisms. When users attempt to access RSS feed endpoints, the system fails to properly validate whether the requesting user possesses the necessary privileges to view the specific feed content. This weakness allows any authenticated or even unauthenticated user to bypass normal access controls and retrieve RSS feed data that contains educational materials, course information, or other potentially sensitive content. The vulnerability specifically affects the permission validation logic that should enforce user capabilities before granting access to feed resources.
From an operational perspective, this vulnerability creates significant risks for educational institutions using Moodle systems. Unauthorized users could potentially gain access to course syllabi, assignment details, student information, or other confidential educational data through the RSS feed mechanism. The impact extends beyond simple information disclosure as it could enable further attacks by providing attackers with knowledge about course structures, content availability, and system organization. This weakness could be exploited by malicious actors to gather intelligence for more sophisticated attacks or to conduct unauthorized data exfiltration.
Organizations should implement immediate mitigations including strengthening the capability checks within the RSS feed access points and ensuring proper user authentication validation before content delivery. System administrators should review and tighten access control policies for RSS feed endpoints, implementing role-based access controls that align with the principle of least privilege. Additionally, regular security audits of feed access mechanisms and monitoring for unauthorized access attempts should be established. The vulnerability aligns with CWE-284 which addresses improper access control and represents a clear violation of the security principle that access to system resources should be strictly controlled based on user permissions and capabilities.
This flaw demonstrates the importance of comprehensive security testing across all system components including seemingly innocuous features like RSS feed readers. The vulnerability highlights how access control mechanisms must be rigorously implemented and validated across all user interaction points within educational platforms. Organizations should also consider implementing additional monitoring and logging for RSS feed access to detect potential exploitation attempts and maintain audit trails for security investigations. The ATT&CK framework would categorize this as a privilege escalation or information gathering technique where adversaries exploit weak access controls to obtain unauthorized data access.