CVE-2025-62399
📋 TL;DR
CVE-2025-62399 allows attackers to perform brute-force attacks against Moodle's mobile and web service authentication endpoints due to insufficient rate limiting. This vulnerability could lead to unauthorized account access by guessing passwords through repeated attempts. All Moodle instances with mobile or web service authentication enabled are affected.
💻 Affected Systems
- Moodle
📦 What is this software?
Moodle by Moodle
Moodle by Moodle
Moodle by Moodle
Moodle by Moodle
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain administrative access to Moodle, compromising all user accounts, sensitive educational data, and potentially using the platform for further attacks.
Likely Case
Attackers compromise student or instructor accounts to access course materials, grades, and personal information, potentially leading to data theft or academic fraud.
If Mitigated
With proper rate limiting and monitoring, attackers may only achieve limited account compromises before detection and blocking.
🎯 Exploit Status
Brute-force attacks are well-understood and easily automated; no authentication required to attempt password guessing.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Moodle security advisories for specific patched versions
Vendor Advisory: https://moodle.org/security/
Restart Required: No
Instructions:
1. Check Moodle security advisory for CVE-2025-62399
2. Update Moodle to the patched version
3. Verify mobile and web service authentication endpoints have rate limiting enabled
🔧 Temporary Workarounds
Implement Web Application Firewall (WAF) Rules
allConfigure WAF to limit authentication attempts per IP address on mobile and web service endpoints
Disable Vulnerable Endpoints
allTemporarily disable mobile app authentication and web services if not required
Navigate to Moodle admin panel > Site administration > Mobile app > Mobile settings > Disable mobile web services
🧯 If You Can't Patch
- Implement strict network-level rate limiting for authentication endpoints using firewalls or load balancers
- Enable detailed logging and monitoring for failed authentication attempts with alert thresholds
🔍 How to Verify
Check if Vulnerable:
Check if mobile or web service authentication endpoints allow unlimited password attempts without rate limitingCheck Version:
Check Moodle version in Site administration > Notifications or via moodle_version table in databaseVerify Fix Applied:
Test authentication endpoints to confirm rate limiting is enforced after patch📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts from single IP address on /webservice/ or /login/token.php endpoints
- Unusual authentication patterns outside normal user behavior
Network Indicators:
- High volume of POST requests to authentication endpoints
- Traffic from tools like Hydra or Burp Suite Intruder
SIEM Query:
source="moodle.log" AND ("authentication failure" OR "failed login") | stats count by src_ip | where count > 10