CVE-2025-28018
📋 TL;DR
This CVE describes a buffer overflow vulnerability in TOTOLINK A800R routers through the downloadFile.cgi endpoint's v14 parameter. Attackers can exploit this to execute arbitrary code or crash the device. Users running affected firmware versions are vulnerable.
💻 Affected Systems
- TOTOLINK A800R
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistence, and lateral movement within the network.
Likely Case
Denial of service (device crash) or limited code execution depending on exploit sophistication.
If Mitigated
Minimal impact if device is isolated from untrusted networks and has strict access controls.
🎯 Exploit Status
Buffer overflow vulnerabilities in embedded devices are frequently weaponized. The provided reference suggests exploit details are available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
Check TOTOLINK website for firmware updates. If available, download and flash via admin interface.
🔧 Temporary Workarounds
Disable WAN access to admin interface
allPrevent external exploitation by blocking internet access to router management.
Access router settings > Administration > Remote Management > Disable
Restrict LAN access
allLimit which internal IPs can access the admin interface.
Access router settings > Firewall > Access Control > Add rules to restrict admin IPs
🧯 If You Can't Patch
- Replace vulnerable device with supported model
- Segment network to isolate router from critical assets
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin panel under System Status or Maintenance.Check Version:
curl -s http://router-ip/version.cgi or check web interfaceVerify Fix Applied:
Verify firmware version is newer than V4.1.2cu.5137_B20200730.📡 Detection & Monitoring
Log Indicators:
- Multiple requests to downloadFile.cgi with long v14 parameters
- Device crash/reboot logs
Network Indicators:
- Unusual HTTP POST requests to downloadFile.cgi from external IPs
SIEM Query:
http.url:*downloadFile.cgi* AND http.param:v14 AND bytes > 1000