CVE-2025-5443
📋 TL;DR
This critical vulnerability in Linksys wireless range extenders allows remote attackers to execute arbitrary operating system commands via command injection in the wireless configuration function. Attackers can exploit this to gain full control of affected devices. All users of listed Linksys RE series range extenders with vulnerable firmware versions are affected.
💻 Affected Systems
- Linksys RE6500
- Linksys RE6250
- Linksys RE6300
- Linksys RE6350
- Linksys RE7000
- Linksys RE9000
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network pivoting to internal systems, and use in botnets or ransomware attacks.
Likely Case
Remote code execution allowing attackers to modify device settings, intercept network traffic, or use device as part of DDoS botnets.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit code available on GitHub. Remote exploitation requires no authentication. Simple HTTP POST request with command injection payload.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.linksys.com/
Restart Required: Yes
Instructions:
1. Check Linksys website for firmware updates. 2. If update available, download and install via web interface. 3. Reboot device after update. 4. Verify firmware version is no longer vulnerable.
🔧 Temporary Workarounds
Network Isolation
allPlace vulnerable devices on isolated VLAN with no internet access and strict firewall rules.
Access Control
linuxBlock external access to device management interface using firewall rules.
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Disable remote management and restrict web interface to trusted internal IPs only
- Replace vulnerable devices with patched or alternative hardware
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface at http://[device-ip]/ or using admin credentials.Check Version:
curl -s http://[device-ip]/ | grep -i firmware || ssh admin@[device-ip] 'cat /etc/version'Verify Fix Applied:
Verify firmware version is updated beyond vulnerable versions listed. Test with controlled exploit attempt if possible.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/wirelessAdvancedHidden
- Commands containing shell metacharacters in HTTP parameters
- Unexpected process execution from web server
Network Indicators:
- HTTP POST to /goform/wirelessAdvancedHidden with ExtChSelector/24GSelector/5GSelector parameters containing ;, |, &, or $()
- Outbound connections from range extender to unknown IPs
SIEM Query:
source="web_logs" AND uri="/goform/wirelessAdvancedHidden" AND (param="ExtChSelector" OR param="24GSelector" OR param="5GSelector") AND value MATCHES "[;|&$()]"