CVE-2025-7524
📋 TL;DR
This critical vulnerability in TOTOLINK T6 routers allows remote attackers to execute arbitrary commands via command injection in the HTTP POST request handler. Attackers can exploit this by manipulating the 'ip' parameter in the setDiagnosisCfg function. All users running the affected firmware version are at risk.
💻 Affected Systems
- TOTOLINK T6
📦 What is this software?
T6 Firmware by Totolink
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attackers to install malware, create persistent backdoors, pivot to internal networks, or brick the device.
Likely Case
Remote code execution leading to device takeover, network traffic interception, or participation in botnets.
If Mitigated
Limited impact if device is behind firewall with strict inbound rules and network segmentation.
🎯 Exploit Status
Proof of concept available on GitHub. Simple HTTP POST request with crafted payload can trigger exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Check vendor website for firmware updates. If update exists: 1. Download latest firmware from official TOTOLINK site. 2. Log into router admin interface. 3. Navigate to firmware upgrade section. 4. Upload and apply new firmware. 5. Reboot router.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to web management interface
Login to router admin → System → Remote Management → Disable
Network Segmentation
allIsolate router management interface from untrusted networks
Configure firewall rules to block external access to port 80/443 on router
🧯 If You Can't Patch
- Replace affected device with supported model
- Implement strict network access controls and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface under System → Firmware Upgrade. If version matches affected version, device is vulnerable.Check Version:
curl -s http://router-ip/cgi-bin/cstecgi.cgi -X POST -d '{"topicurl":"setting/getMainDiagCfg"}' | grep versionVerify Fix Applied:
Verify firmware version has changed from affected version. Test if crafted POST requests to /cgi-bin/cstecgi.cgi with command injection payloads are rejected.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /cgi-bin/cstecgi.cgi
- Commands with shell metacharacters in ip parameter
- Failed authentication attempts followed by exploitation
Network Indicators:
- HTTP POST to /cgi-bin/cstecgi.cgi with suspicious ip parameter values
- Outbound connections from router to unexpected destinations
SIEM Query:
source="router_logs" AND uri_path="/cgi-bin/cstecgi.cgi" AND (method="POST" AND (param="ip" AND value MATCHES "[;&|`$()]"))🔗 References
- https://github.com/ElvisBlue/Public/blob/main/Vuln/2.md
- https://github.com/ElvisBlue/Public/blob/main/Vuln/2.md#poc
- https://vuldb.com/?ctiid.316221
- https://vuldb.com/?id.316221
- https://vuldb.com/?submit.612935
- https://www.totolink.net/
- https://www.youtube.com/watch?v=T62BuSoHmoM
- https://github.com/ElvisBlue/Public/blob/main/Vuln/2.md
