CVE-2025-66507
📋 TL;DR
CVE-2025-66507 is an authentication bypass vulnerability in 1Panel that allows unauthenticated attackers to disable CAPTCHA verification by manipulating client-controlled parameters. This enables automated login attempts and significantly increases the risk of account takeover. All users running 1Panel versions 2.0.13 and below are affected.
💻 Affected Systems
- 1Panel
📦 What is this software?
1panel by Fit2cloud
⚠️ Risk & Real-World Impact
Worst Case
Successful brute-force attacks leading to complete system compromise, unauthorized administrative access, and potential lateral movement within the network.
Likely Case
Automated credential stuffing attacks resulting in unauthorized access to 1Panel administrative interfaces and potential server management control.
If Mitigated
Limited to failed login attempts with proper monitoring and alerting in place.
🎯 Exploit Status
The vulnerability involves simple parameter manipulation that can be automated. No authentication required makes exploitation trivial.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.0.14
Vendor Advisory: https://github.com/1Panel-dev/1Panel/security/advisories/GHSA-qmg5-v42x-qqhq
Restart Required: Yes
Instructions:
1. Backup your current 1Panel configuration and data. 2. Stop the 1Panel service. 3. Update to version 2.0.14 using the official upgrade command or by downloading from GitHub releases. 4. Restart the 1Panel service. 5. Verify the update was successful.
🔧 Temporary Workarounds
Network Access Restriction
linuxRestrict access to 1Panel web interface to trusted IP addresses only using firewall rules.
sudo ufw allow from TRUSTED_IP to any port 1PANEL_PORT
sudo iptables -A INPUT -p tcp --dport 1PANEL_PORT -s TRUSTED_IP -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 1PANEL_PORT -j DROP
Rate Limiting
linuxImplement rate limiting on login endpoints to mitigate brute-force attempts.
sudo apt-get install nginx-extras
Add rate limiting configuration to nginx: limit_req_zone $binary_remote_addr zone=login:10m rate=5r/m;
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to isolate 1Panel from untrusted networks.
- Enable multi-factor authentication (MFA) if supported and implement comprehensive login monitoring with alerting.
🔍 How to Verify
Check if Vulnerable:
Check your 1Panel version. If it's 2.0.13 or below, you are vulnerable. Attempt to access the login page and inspect network requests for CAPTCHA-related parameters.Check Version:
1pctl versionVerify Fix Applied:
After updating to 2.0.14, verify that CAPTCHA verification cannot be bypassed by manipulating client parameters. Test login attempts with and without proper CAPTCHA completion.📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts from single IP addresses
- Login attempts without CAPTCHA verification logs
- Unusual parameter values in authentication requests
Network Indicators:
- High volume of POST requests to login endpoints
- Patterned login attempts suggesting automation
- Requests with modified CAPTCHA-related parameters
SIEM Query:
source="1panel.logs" ("login failed" OR "authentication failure") | stats count by src_ip | where count > 10