CVE-2025-5685
📋 TL;DR
A critical stack-based buffer overflow vulnerability in Tenda CH22 routers allows remote attackers to execute arbitrary code by manipulating the 'page' parameter in the formNatlimit function. This affects Tenda CH22 router version 1.0.0.1. Attackers can exploit this remotely without authentication to potentially take full control of affected routers.
💻 Affected Systems
- Tenda CH22 router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete router compromise, allowing attackers to intercept traffic, modify DNS settings, install malware, or pivot to internal networks.
Likely Case
Router takeover enabling traffic interception, credential theft, and network reconnaissance for further attacks.
If Mitigated
Limited impact if router is behind firewall with restricted WAN access, though internal attacks remain possible.
🎯 Exploit Status
Exploit details are publicly available on GitHub, making weaponization likely. 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 CH22. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router administration interface
Network segmentation
allIsolate router management interface to trusted network segment
🧯 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 via admin interface. If version is 1.0.0.1, the device is vulnerable.Check Version:
Access router web interface at default gateway IP and check firmware version in system statusVerify Fix Applied:
Verify firmware version has been updated to a version later than 1.0.0.1 via router admin interface.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/Natlimit with manipulated page parameter
- Multiple failed buffer overflow attempts in router logs
Network Indicators:
- Unusual traffic patterns to router management interface from external IPs
- POST requests to /goform/Natlimit with abnormal parameter lengths
SIEM Query:
source="router_logs" AND (uri="/goform/Natlimit" AND param="page" AND length(value)>100)🔗 References
- https://github.com/xubeining/Cve_report/blob/main/A%20remote%20code%20execution%20vulnerability%20in%20the%20router%20CH22%20V1.0.0.1%20manufactured%20by%20Shenzhen%20Jixiangtengda%20Technology%20Co.%2C%20Ltd1.md
- https://vuldb.com/?ctiid.311169
- https://vuldb.com/?id.311169
- https://vuldb.com/?submit.590153
- https://www.tenda.com.cn/
- https://github.com/xubeining/Cve_report/blob/main/A%20remote%20code%20execution%20vulnerability%20in%20the%20router%20CH22%20V1.0.0.1%20manufactured%20by%20Shenzhen%20Jixiangtengda%20Technology%20Co.%2C%20Ltd1.md
