CVE-2024-35395
📋 TL;DR
This vulnerability involves a hardcoded root password in the TOTOLINK CP900L router's sample shadow file. Attackers can use this password to gain administrative access to affected devices. All users running the vulnerable firmware version are affected.
💻 Affected Systems
- TOTOLINK CP900L
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to intercept traffic, modify configurations, install malware, or use the device as a pivot point into the network.
Likely Case
Unauthorized administrative access leading to network surveillance, DNS hijacking, or credential theft from connected devices.
If Mitigated
Limited impact if device is behind firewall with strict inbound rules and network segmentation prevents lateral movement.
🎯 Exploit Status
Exploitation requires only knowledge of the hardcoded password and SSH/Telnet access to the device. Public GitHub repository contains detailed information.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: http://totolink.com
Restart Required: No
Instructions:
1. Check vendor website for firmware updates
2. If update available, download and install via web interface
3. Verify /etc/shadow file does not contain hardcoded password after update
🔧 Temporary Workarounds
Change root password
linuxManually change the root password to a strong, unique value
passwd root
Disable remote administration
allTurn off SSH/Telnet access from WAN interface
🧯 If You Can't Patch
- Isolate affected devices in separate VLAN with strict firewall rules
- Implement network monitoring for suspicious authentication attempts to router
🔍 How to Verify
Check if Vulnerable:
Check if /etc/shadow or /etc/shadow.sample contains hardcoded password: grep 'root:' /etc/shadowCheck Version:
Check web interface or run: cat /proc/versionVerify Fix Applied:
Verify root password has been changed and is not the default hardcoded value📡 Detection & Monitoring
Log Indicators:
- Failed SSH/Telnet login attempts followed by successful root login
- Multiple root login attempts from unusual IPs
Network Indicators:
- SSH/Telnet connections to router from external IPs
- Unusual outbound traffic from router
SIEM Query:
source="router.log" ("Accepted password for root" OR "login as root")