CVE-2025-27129
📋 TL;DR
An authentication bypass vulnerability in Tenda AC6 routers allows attackers to bypass HTTP authentication and execute arbitrary code. This affects Tenda AC6 V5.0 routers running firmware version V02.03.01.110. Attackers can exploit this remotely without authentication.
💻 Affected Systems
- Tenda AC6 V5.0
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router leading to network infiltration, data interception, malware deployment, and persistent backdoor access.
Likely Case
Router takeover enabling traffic monitoring, DNS hijacking, credential theft, and lateral movement into connected networks.
If Mitigated
Limited impact if router is behind firewall with restricted WAN access and strong network segmentation.
🎯 Exploit Status
Talos Intelligence has published technical details. The authentication bypass leads directly to RCE, making exploitation straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware for AC6 V5.0. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and install new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router administration interface
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace affected router with different model or vendor
- Implement strict firewall rules blocking all WAN access to router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is V02.03.01.110, the device is vulnerable.Check Version:
Login to router admin interface and check System Status or Firmware Version pageVerify Fix Applied:
After firmware update, verify version is no longer V02.03.01.110. Test authentication functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual authentication attempts
- HTTP requests bypassing auth
- Unexpected firmware or configuration changes
Network Indicators:
- Suspicious HTTP traffic to router management port
- Unexpected outbound connections from router
SIEM Query:
source_ip=router_ip AND (http_method=POST OR http_method=GET) AND uri_contains="/goform/" AND NOT user_agent="normal"