CVE-2025-44654
📋 TL;DR
This vulnerability in Linksys E2500 routers with vsftpd configuration allows attackers to bypass chroot restrictions and access system files. Attackers could escalate privileges, steal sensitive data, or use the compromised device to attack internal networks. Only Linksys E2500 routers running firmware version 3.0.04.002 are affected.
💻 Affected Systems
- Linksys E2500
📦 What is this software?
⚠️ 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 router configuration files, credential harvesting, and use as pivot point for internal reconnaissance.
If Mitigated
Limited to FTP service compromise if proper network segmentation and access controls are implemented.
🎯 Exploit Status
Exploitation requires FTP access credentials. Public proof-of-concept demonstrates the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Check Linksys website for firmware updates. Consider upgrading to newer router model if available.
🔧 Temporary Workarounds
Disable vsftpd service
linuxCompletely disable the FTP service if not required
service vsftpd stop
chkconfig vsftpd off
Modify vsftpd configuration
linuxSet chroot_local_user=NO in vsftpd configuration file
sed -i 's/chroot_local_user=YES/chroot_local_user=NO/g' /etc/vsftpd.conf
service vsftpd restart
🧯 If You Can't Patch
- Implement strict network segmentation to isolate router from critical internal networks
- Disable FTP access from untrusted networks and implement IP whitelisting
🔍 How to Verify
Check if Vulnerable:
Check /etc/vsftpd.conf for 'chroot_local_user=YES' and verify firmware version is 3.0.04.002Check Version:
cat /proc/version or check router web interface for firmware versionVerify Fix Applied:
Verify chroot_local_user=NO in vsftpd.conf and confirm vsftpd service is stopped or properly configured📡 Detection & Monitoring
Log Indicators:
- Unusual FTP login attempts
- FTP commands accessing system directories
- Failed chroot operations in vsftpd logs
Network Indicators:
- Unexpected FTP traffic to router
- FTP connections followed by unusual internal network scans
SIEM Query:
source="vsftpd.log" AND ("chroot" OR "/etc/" OR "/root/")