CVE-2025-67856
📋 TL;DR
An authorization logic flaw in Moodle's badge awarding system allows users to obtain badges without proper role verification. This affects all Moodle instances with badge functionality enabled, potentially enabling unauthorized privilege escalation.
💻 Affected Systems
- Moodle
📦 What is this software?
Moodle by Moodle
Moodle by Moodle
Moodle by Moodle
Moodle by Moodle
Moodle by Moodle
⚠️ Risk & Real-World Impact
Worst Case
Attackers could gain administrative badges or access to restricted course materials, leading to full system compromise through privilege escalation chains.
Likely Case
Unauthorized users obtain badges they shouldn't have access to, potentially gaining access to restricted course content or features.
If Mitigated
Limited to badge system only with no direct system access, though badge integrity is compromised.
🎯 Exploit Status
Requires authenticated access but minimal technical skill to exploit the authorization flaw.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Moodle security advisories for specific fixed version
Vendor Advisory: https://moodle.org/security/
Restart Required: No
Instructions:
1. Check Moodle security advisory for CVE-2025-67856. 2. Update to the patched version. 3. Clear Moodle caches after update.
🔧 Temporary Workarounds
Disable Badge System
allTemporarily disable the badge awarding functionality until patched
Navigate to Site administration > Badges > Manage badges > Disable badge system
🧯 If You Can't Patch
- Implement strict role-based access controls and audit badge assignments regularly
- Monitor badge awarding logs for suspicious activity and implement alerting
🔍 How to Verify
Check if Vulnerable:
Check if badge system is enabled and test badge awarding with insufficient permissionsCheck Version:
Check Moodle version in Site administration > NotificationsVerify Fix Applied:
Verify badge awarding now requires proper role permissions after update📡 Detection & Monitoring
Log Indicators:
- Unexpected badge awards to users without proper roles
- Multiple badge awards in short timeframes
Network Indicators:
- HTTP requests to badge awarding endpoints with unusual parameters
SIEM Query:
source="moodle_logs" AND (event="badge_awarded" AND NOT user_role="required_role")