CVE-2025-28022
📋 TL;DR
This CVE describes a buffer overflow vulnerability in TOTOLINK A810R routers through the downloadFile.cgi endpoint's v25 parameter. Attackers can exploit this to execute arbitrary code or crash the device. Users of affected TOTOLINK A810R routers are impacted.
💻 Affected Systems
- TOTOLINK A810R
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistence, and network infiltration.
Likely Case
Device crash (DoS) or limited code execution affecting router functionality.
If Mitigated
No impact if the vulnerable endpoint is disabled or inaccessible.
🎯 Exploit Status
References suggest proof-of-concept exists; buffer overflow vulnerabilities in routers are commonly weaponized.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not found in provided references
Restart Required: Yes
Instructions:
Check TOTOLINK website for firmware updates. If available, download and flash via admin interface.
🔧 Temporary Workarounds
Disable downloadFile.cgi access
linuxBlock access to the vulnerable CGI script via firewall or router configuration.
iptables -A INPUT -p tcp --dport 80 -m string --string "downloadFile.cgi" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "downloadFile.cgi" --algo bm -j DROP
Restrict web interface access
allLimit router admin interface access to trusted IPs only.
Configure in router admin: Firewall > Access Control > Allow only specific IPs
🧯 If You Can't Patch
- Isolate the router on a dedicated network segment.
- Monitor for exploitation attempts and unusual traffic to/from the router.
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface (typically under System > Firmware Upgrade).Check Version:
curl -s http://router-ip/version.cgi or check web interfaceVerify Fix Applied:
Verify firmware version is updated beyond V4.1.2cu.5182_B20201026.📡 Detection & Monitoring
Log Indicators:
- HTTP requests to downloadFile.cgi with long v25 parameters
- Router crash/reboot logs
Network Indicators:
- Unusual outbound connections from router
- Exploit pattern traffic to router IP
SIEM Query:
source="router_logs" AND "downloadFile.cgi" AND "v25="