CVE-2024-22212
📋 TL;DR
CVE-2024-22212 is an authentication bypass vulnerability in Nextcloud Global Site Selector that allows attackers to authenticate as any user due to a flaw in password verification. This affects all Nextcloud deployments using the Global Site Selector extension. Attackers can gain unauthorized access to user accounts and potentially administrative privileges.
💻 Affected Systems
- Nextcloud Global Site Selector
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of all Nextcloud instances managed by Global Site Selector, allowing attackers to access sensitive user data, modify configurations, and potentially pivot to other systems.
Likely Case
Unauthorized access to user accounts leading to data theft, privilege escalation, and potential lateral movement within the Nextcloud environment.
If Mitigated
Limited impact if proper network segmentation and access controls are in place, but authentication bypass still poses significant risk.
🎯 Exploit Status
The vulnerability is in authentication logic, making exploitation straightforward once the attack vector is understood. No authentication required to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.4.1, 2.1.2, 2.3.4, or 2.4.5
Vendor Advisory: https://github.com/nextcloud/security-advisories/security/advisories/GHSA-vj5q-f63m-wp77
Restart Required: Yes
Instructions:
1. Backup your Nextcloud instance and database. 2. Update Global Site Selector via Nextcloud app store or manual installation. 3. Restart web server (Apache/Nginx) and PHP-FPM. 4. Clear Nextcloud cache via occ command: sudo -u www-data php occ files:scan --all
🔧 Temporary Workarounds
Disable Global Site Selector
linuxTemporarily disable the vulnerable extension until patching is possible
sudo -u www-data php occ app:disable globalsiteselector
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the Global Site Selector endpoint
- Enable detailed authentication logging and monitor for suspicious login attempts across all user accounts
🔍 How to Verify
Check if Vulnerable:
Check Global Site Selector version in Nextcloud admin interface under Apps section or run: sudo -u www-data php occ app:list | grep globalsiteselectorCheck Version:
sudo -u www-data php occ app:list | grep -A2 'globalsiteselector'Verify Fix Applied:
Verify version shows 1.4.1, 2.1.2, 2.3.4, or 2.4.5 after update. Test authentication with known credentials.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful login from same IP
- User logins from unusual locations or IPs
- Authentication requests to Global Site Selector endpoints
Network Indicators:
- Unusual authentication traffic patterns to /index.php/apps/globalsiteselector/ endpoints
- Multiple authentication attempts in short timeframes
SIEM Query:
source="nextcloud.log" AND ("globalsiteselector" OR "authentication") AND (status="200" OR "success") | stats count by src_ip, user🔗 References
- https://github.com/nextcloud/globalsiteselector/commit/ab5da57190d5bbc79079ce4109b6bcccccd893ee
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-vj5q-f63m-wp77
- https://hackerone.com/reports/2248689
- https://github.com/nextcloud/globalsiteselector/commit/ab5da57190d5bbc79079ce4109b6bcccccd893ee
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-vj5q-f63m-wp77
- https://hackerone.com/reports/2248689
