CVE-2025-67856 Overview
A significant authorization logic flaw has been identified in Moodle, the popular open-source learning management system (LMS). This vulnerability stems from incomplete role checks during the badge awarding process, which allows badges to be granted without proper verification. The flaw could enable unauthorized users to obtain badges they are not entitled to, potentially leading to privilege escalation or unauthorized access to certain features within the platform.
Critical Impact
Unauthorized badge acquisition could lead to privilege escalation and access to restricted features in Moodle environments.
Affected Products
- Moodle LMS (specific versions not disclosed in advisory)
Discovery Timeline
- February 3, 2026 - CVE-2025-67856 published to NVD
- February 3, 2026 - Last updated in NVD database
Technical Details for CVE-2025-67856
Vulnerability Analysis
This authorization bypass vulnerability exists in Moodle's badge awarding functionality. The core issue lies in the incomplete implementation of role-based access control (RBAC) checks when processing badge award requests. When a user initiates a badge award action, the system fails to comprehensively validate whether the requesting user has the appropriate permissions and role assignments necessary to grant or receive the badge.
The vulnerability allows authenticated users with low-level privileges to bypass intended authorization controls. This could manifest in scenarios where users manipulate badge award requests to grant themselves or others badges that should require higher privilege levels or specific course completions.
Root Cause
The root cause of this vulnerability is an authorization logic flaw resulting from incomplete role verification during the badge awarding workflow. The system's access control mechanism does not perform exhaustive checks against all required permission levels and role assignments before processing badge award operations. This incomplete validation creates a gap where certain authorization conditions can be bypassed by crafting requests that satisfy some but not all of the intended security checks.
Attack Vector
This vulnerability is exploitable over the network by authenticated users with low-level privileges. An attacker would need to:
- Authenticate to the Moodle instance with a valid user account
- Interact with the badge awarding functionality
- Manipulate requests or parameters to bypass incomplete role checks
- Successfully obtain badges without meeting the proper criteria
The attack requires no user interaction from victims and does not affect the underlying system's availability. The primary impacts are unauthorized access to confidential information associated with badge privileges and integrity violations through improper badge assignments.
For technical implementation details, refer to the Red Hat CVE-2025-67856 Advisory and Red Hat Bug Report #2423864.
Detection Methods for CVE-2025-67856
Indicators of Compromise
- Unusual badge award activity for users who have not completed required criteria
- Unexpected privilege escalation events following badge acquisitions
- Anomalous API requests to badge-related endpoints from low-privilege accounts
- Audit logs showing badge awards without corresponding completion records
Detection Strategies
- Monitor Moodle audit logs for badge award events that lack corresponding prerequisite completions
- Implement alerting for users receiving multiple badges in rapid succession
- Review access patterns to badge management endpoints for anomalous behavior
- Cross-reference badge awards against course completion and role assignment records
Monitoring Recommendations
- Enable comprehensive logging for all badge-related operations in Moodle
- Configure SIEM rules to detect authorization bypass patterns in LMS traffic
- Establish baseline metrics for normal badge award frequency and deviation thresholds
- Implement periodic audits of badge assignments against expected criteria
How to Mitigate CVE-2025-67856
Immediate Actions Required
- Review and audit all recent badge awards for unauthorized or suspicious assignments
- Implement additional authorization checks at the web application firewall level
- Restrict badge awarding capabilities to trusted administrator accounts temporarily
- Monitor badge-related API endpoints for exploitation attempts
Patch Information
Organizations running Moodle should consult the official security advisories for patch availability. For the latest information on remediation:
Apply vendor-provided security updates as soon as they become available. Ensure all Moodle instances are updated to the latest patched version.
Workarounds
- Disable badge functionality temporarily if not critical to operations
- Implement custom access control rules at the reverse proxy or WAF level to restrict badge endpoints
- Manually review and approve all badge awards through administrative workflows
- Enforce stricter role-based access controls through Moodle's permission management
# Example: Restrict access to badge endpoints at web server level (Apache)
# Add to your Moodle virtual host configuration
<LocationMatch "^/badges/">
Require user admin
# Or restrict to specific IP ranges
# Require ip 10.0.0.0/8
</LocationMatch>
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
