CVE-2025-12595
📋 TL;DR
A buffer overflow vulnerability in Tenda AC23 routers allows remote attackers to execute arbitrary code by manipulating the argument list in the formSetVirtualSer function. This affects Tenda AC23 routers running firmware version 16.03.07.52. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Tenda AC23
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, creation of persistent backdoors, lateral movement to internal networks, and botnet recruitment.
Likely Case
Remote code execution resulting in device takeover, credential theft, and use as pivot point for internal network attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit code is available on GitHub. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware for AC23. 3. Log into router admin interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Log into router admin > Advanced > System Tools > Remote Management > Disable
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Block inbound access to router web interface (port 80/443) at network perimeter
- Replace vulnerable devices with patched or different vendor equipment
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface: System Status > Firmware Version. If version is 16.03.07.52, device is vulnerable.Check Version:
curl -s http://router-ip/ | grep -i firmwareVerify Fix Applied:
After firmware update, verify version is no longer 16.03.07.52. Test if /goform/SetVirtualServerCfg endpoint still accepts malformed input.📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/SetVirtualServerCfg with long parameters
- Unusual process execution in router logs
- Failed authentication attempts followed by exploitation attempts
Network Indicators:
- Unusual outbound connections from router
- Traffic to known exploit repositories
- POST requests with buffer overflow patterns to router IP
SIEM Query:
source="router_logs" AND (uri="/goform/SetVirtualServerCfg" AND content_length>1000) OR (process="malicious_binary" AND host="router")