CVE-2025-44655
📋 TL;DR
This vulnerability in TOTOLink routers allows attackers to bypass FTP directory restrictions due to misconfigured vsftpd settings. Attackers can access system files, escalate privileges, or use the compromised device to attack internal networks. Users of TOTOLink A7100RU V7.4, A950RG V5.9, and T10 V5.9 routers are affected.
💻 Affected Systems
- TOTOLink A7100RU
- TOTOLink A950RG
- TOTOLink T10
📦 What is this software?
T10 Firmware by Totolink
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise leading to complete router takeover, credential theft, lateral movement to internal networks, and persistent backdoor installation.
Likely Case
Unauthorized access to sensitive system files, configuration extraction, and potential privilege escalation to root.
If Mitigated
Limited impact if FTP service is disabled or properly firewalled, though the vulnerability remains present.
🎯 Exploit Status
Exploitation requires FTP access but is straightforward once access is obtained. The GitHub gist provides technical details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: http://totolink.com
Restart Required: Yes
Instructions:
1. Check TOTOLink website for firmware updates. 2. Download appropriate firmware for your model. 3. Upload via router admin interface. 4. Reboot router after update.
🔧 Temporary Workarounds
Disable FTP Service
allCompletely disable the FTP service if not required.
Check router admin interface for FTP settings and disable
Modify vsftpd Configuration
linuxChange chroot_local_user to NO in vsftpd.conf
Edit /etc/vsftpd.conf
Change 'chroot_local_user=YES' to 'chroot_local_user=NO'
Restart vsftpd service
🧯 If You Can't Patch
- Disable FTP service entirely through router administration interface
- Implement strict firewall rules to block FTP access from untrusted networks
🔍 How to Verify
Check if Vulnerable:
Check if FTP service is enabled and accessible. Examine /etc/vsftpd.conf for 'chroot_local_user=YES' setting.Check Version:
Check router admin interface or use 'cat /proc/version' via SSH if availableVerify Fix Applied:
Verify 'chroot_local_user=NO' in vsftpd.conf and confirm FTP service is either disabled or properly restricted.📡 Detection & Monitoring
Log Indicators:
- Unusual FTP login attempts
- FTP access to system directories
- Failed chroot operations in vsftpd logs
Network Indicators:
- Unexpected FTP traffic to router
- FTP connections from unusual sources
SIEM Query:
source="vsftpd" AND (event="CHROOT" OR event="ROOT")