CVE-2026-2527
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary commands on Wavlink WL-WN579A3 routers by manipulating the 'key' parameter in the login.cgi endpoint. Attackers can gain full control of affected devices without authentication. All users of Wavlink WL-WN579A3 routers with firmware up to February 19, 2021 are affected.
💻 Affected Systems
- Wavlink WL-WN579A3
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing installation of persistent backdoors, network pivoting, credential theft, and participation in botnets.
Likely Case
Remote code execution leading to device takeover, network surveillance, and potential lateral movement within the network.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit details are available on GitHub. The attack requires only HTTP requests to the vulnerable endpoint with crafted parameters.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
No official patch available. Vendor has not responded to disclosure. Consider replacing affected devices or implementing workarounds.
🔧 Temporary Workarounds
Block CGI Endpoint Access
linuxUse firewall rules to block access to the vulnerable /cgi-bin/login.cgi endpoint
iptables -A INPUT -p tcp --dport 80 -m string --string "/cgi-bin/login.cgi" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/cgi-bin/login.cgi" --algo bm -j DROP
Disable Web Interface
allDisable the router's web management interface if not required for operations
🧯 If You Can't Patch
- Isolate affected routers in a separate VLAN with strict network segmentation
- Implement strict egress filtering to prevent command and control communication
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface at http://[router-ip]/cgi-bin/status.cgi or SSH if enabled. Versions <= 20210219 are vulnerable.Check Version:
curl -s http://[router-ip]/cgi-bin/status.cgi | grep -i versionVerify Fix Applied:
Test with controlled exploit attempt using curl: curl -X POST http://[router-ip]/cgi-bin/login.cgi -d 'key=test;id' - check if command executes.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /cgi-bin/login.cgi with shell metacharacters in parameters
- Unusual process execution from web server context
- Failed authentication attempts followed by successful command execution
Network Indicators:
- HTTP traffic to router IP on port 80/443 containing shell commands in POST data
- Outbound connections from router to unusual external IPs following web requests
SIEM Query:
source="router-logs" AND url="/cgi-bin/login.cgi" AND (method="POST" OR params CONTAINS ";" OR params CONTAINS "|" OR params CONTAINS "`")