CVE-2024-26566
📋 TL;DR
CVE-2024-26566 is an authentication bypass vulnerability in Cute Http File Server v3.1 that allows remote attackers to escalate privileges by exploiting flaws in the password verification component. This affects all users running the vulnerable version of the file server software, potentially exposing sensitive files and system access.
💻 Affected Systems
- Cute Http File Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where an attacker gains administrative access to the file server, can read/modify/delete all files, execute arbitrary commands, and potentially pivot to other systems.
Likely Case
Unauthorized access to sensitive files stored on the server, data exfiltration, and potential privilege escalation to administrative functions.
If Mitigated
Limited impact with proper network segmentation, strong authentication controls, and monitoring in place to detect unauthorized access attempts.
🎯 Exploit Status
Public proof-of-concept code is available on GitHub. The vulnerability requires minimal technical skill to exploit and can be automated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 3.2 or later
Vendor Advisory: http://cute.com
Restart Required: Yes
Instructions:
1. Download the latest version from the official website. 2. Stop the current Cute Http File Server service. 3. Backup configuration files. 4. Install the new version. 5. Restart the service.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict network access to the file server using firewall rules to only allow trusted IP addresses.
# Linux iptables example: iptables -A INPUT -p tcp --dport [PORT] -s [TRUSTED_IP] -j ACCEPT
# Windows firewall: New-NetFirewallRule -DisplayName 'CHFS Access' -Direction Inbound -Protocol TCP -LocalPort [PORT] -RemoteAddress [TRUSTED_IP] -Action Allow
Authentication Proxy
allPlace the file server behind a reverse proxy with additional authentication layer.
# Nginx basic auth example: auth_basic 'Restricted'; auth_basic_user_file /etc/nginx/.htpasswd;
🧯 If You Can't Patch
- Immediately restrict network access to only necessary users/systems using firewall rules
- Implement additional authentication layer (VPN, reverse proxy with auth) in front of the vulnerable service
🔍 How to Verify
Check if Vulnerable:
Check the server version in the web interface or configuration files. If version is 3.1, the system is vulnerable.Check Version:
# Check version in web interface or look for version information in server logs and configuration filesVerify Fix Applied:
After patching, verify the version shows 3.2 or later and test authentication with valid and invalid credentials.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful access
- Authentication bypass patterns in access logs
- Unusual file access patterns from new IP addresses
Network Indicators:
- HTTP requests attempting authentication bypass patterns
- Unusual traffic to file server authentication endpoints
SIEM Query:
source='chfs.log' AND (event_type='auth_failure' OR event_type='auth_bypass') | stats count by src_ip🔗 References
- http://cute.com
- https://github.com/GZLDL/CVE/blob/main/CVE-2024-26566/CVE-2024-26566%20English.md
- https://github.com/GZLDL/CVE/tree/main/Cute%20Http%20File%20Server%20JWT
- http://cute.com
- https://github.com/GZLDL/CVE/blob/main/CVE-2024-26566/CVE-2024-26566%20English.md
- https://github.com/GZLDL/CVE/tree/main/Cute%20Http%20File%20Server%20JWT
