CVE-2025-66581
📋 TL;DR
Frappe LMS versions before 2.41.0 have an authorization bypass vulnerability where authenticated users can perform actions beyond their assigned roles. The flaw occurs because server-side endpoints rely on client-side checks instead of enforcing proper permissions. This affects all users of vulnerable Frappe LMS instances, particularly allowing students to perform instructor/admin actions.
💻 Affected Systems
- Frappe Learning Management System
📦 What is this software?
Learning by Frappe
⚠️ Risk & Real-World Impact
Worst Case
A student could gain administrative privileges, modify course content, access sensitive user data, or disrupt the entire learning platform.
Likely Case
Students could modify their own grades, access other students' submissions, or perform unauthorized course modifications.
If Mitigated
With proper network segmentation and monitoring, impact would be limited to unauthorized actions within the user's current course context.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward via API manipulation. No public exploit code is known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.41.0
Vendor Advisory: https://github.com/frappe/lms/security/advisories/GHSA-2ch7-c74m-432m
Restart Required: Yes
Instructions:
1. Backup your Frappe LMS instance. 2. Update to version 2.41.0 using the Frappe update mechanism. 3. Restart the application server. 4. Verify the update was successful.
🔧 Temporary Workarounds
API Rate Limiting and Monitoring
allImplement rate limiting and enhanced logging on API endpoints to detect suspicious activity
Network Segmentation
allRestrict API access to trusted networks only
🧯 If You Can't Patch
- Implement strict network access controls to limit API access to trusted IPs only
- Enable detailed audit logging for all API calls and monitor for unauthorized role-based actions
🔍 How to Verify
Check if Vulnerable:
Check if Frappe LMS version is below 2.41.0 in the system settings or via the admin interfaceCheck Version:
Check the Frappe LMS admin dashboard or run bench version if using Frappe BenchVerify Fix Applied:
Confirm version is 2.41.0 or higher and test that low-privilege users cannot perform admin/instructor actions via API📡 Detection & Monitoring
Log Indicators:
- API calls from low-privilege users performing admin/instructor actions
- Unusual pattern of role-based API access
Network Indicators:
- Unusual API request patterns from student accounts
- POST/PUT requests to privileged endpoints from non-privileged users
SIEM Query:
source="frappe_lms" AND (user_role="Student" AND action IN ("create_course", "modify_grade", "delete_content"))