CVE-2024-38277
📋 TL;DR
This vulnerability allows an attacker to use a QR login key interchangeably with an auto-login key, potentially bypassing authentication mechanisms. It affects systems using the vulnerable authentication implementation, particularly Moodle installations with QR login enabled.
💻 Affected Systems
- Moodle
📦 What is this software?
Fedora by Fedoraproject
Fedora by Fedoraproject
Moodle by Moodle
Moodle by Moodle
Moodle by Moodle
Moodle by Moodle
⚠️ Risk & Real-World Impact
Worst Case
An attacker could gain unauthorized access to user accounts by reusing QR login keys for auto-login, leading to account takeover and potential data exposure.
Likely Case
Limited account compromise for users who have generated QR login keys, allowing attackers to bypass normal authentication flows.
If Mitigated
With proper key separation, authentication remains secure and keys cannot be reused across different authentication methods.
🎯 Exploit Status
Exploitation requires obtaining a user's QR login key and understanding the authentication flow; not trivial but feasible for determined attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Moodle security releases; typically fixed in security updates following CVE publication.
Vendor Advisory: https://moodle.org/mod/forum/discuss.php?d=459502
Restart Required: No
Instructions:
1. Update Moodle to the latest security release. 2. Verify the update includes the fix for CVE-2024-38277. 3. Test QR login functionality to ensure proper key separation.
🔧 Temporary Workarounds
Disable QR Login
allTemporarily disable QR login feature until patched to prevent exploitation.
Navigate to Moodle admin panel > Site administration > Plugins > Authentication > Manage authentication > Disable QR login
🧯 If You Can't Patch
- Monitor authentication logs for unusual QR login or auto-login attempts
- Implement additional authentication factors for sensitive accounts
🔍 How to Verify
Check if Vulnerable:
Check if QR login keys can be used for auto-login by testing with generated keys; review Moodle version against security advisories.Check Version:
Check Moodle version via admin panel or by examining version.php file in Moodle root directory.Verify Fix Applied:
After patching, test that QR login keys are unique and cannot be reused for auto-login; verify version is updated.📡 Detection & Monitoring
Log Indicators:
- Multiple authentication attempts using the same key for different methods
- Unusual auto-login events from QR login sources
Network Indicators:
- Repeated authentication requests with similar key patterns
SIEM Query:
Example: auth_method IN ('qr_login', 'auto_login') AND same_key_used_count > 1🔗 References
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/F7AZYR7EXV6E5SQE2GYTNQE3NOENJCQ6/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GHTIX55J4Q4LEOMLNEA4OZSWVEENQX7E/
- https://moodle.org/mod/forum/discuss.php?d=459502
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/F7AZYR7EXV6E5SQE2GYTNQE3NOENJCQ6/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GHTIX55J4Q4LEOMLNEA4OZSWVEENQX7E/
- https://moodle.org/mod/forum/discuss.php?d=459502
