CVE-2026-2203
📋 TL;DR
A buffer overflow vulnerability exists in Tenda AC8 routers version 16.03.33.05. Remote attackers can exploit this by sending specially crafted requests to the /goform/fast_setting_wifi_set endpoint, potentially allowing arbitrary code execution. This affects users with vulnerable Tenda AC8 routers exposed to untrusted networks.
💻 Affected Systems
- Tenda AC8
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, credential theft, network pivoting, and persistent backdoor installation.
Likely Case
Router compromise allowing traffic interception, DNS hijacking, or device bricking through memory corruption.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Public proof-of-concept available; remote exploitation without authentication is possible.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Unknown
Restart Required: No
Instructions:
Check Tenda official website for firmware updates; if unavailable, consider workarounds or replacement.
🔧 Temporary Workarounds
Block External Access
allRestrict WAN access to router management interface using firewall rules.
Disable Remote Management
allTurn off remote administration features in router settings.
🧯 If You Can't Patch
- Isolate vulnerable router in separate VLAN with strict network segmentation.
- Monitor network traffic for unusual HTTP requests to /goform/fast_setting_wifi_set endpoint.
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at 192.168.0.1 or 192.168.1.1; if version is 16.03.33.05, device is vulnerable.Check Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version has been updated to a version later than 16.03.33.05.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /goform/fast_setting_wifi_set with abnormal timeZone parameter values
Network Indicators:
- Unusual HTTP traffic to router management port (typically 80/443) from external IPs
SIEM Query:
source="router_logs" AND uri="/goform/fast_setting_wifi_set" AND method="POST"🔗 References
- https://github.com/SunnyYANGyaya/cuicuishark-sheep-fishIOT/blob/main/Tenda/AC8/fastsettingwifiset-timezome.md
- https://github.com/SunnyYANGyaya/cuicuishark-sheep-fishIOT/blob/main/Tenda/AC8/fastsettingwifiset-timezome.md#poc
- https://vuldb.com/?ctiid.344906
- https://vuldb.com/?id.344906
- https://vuldb.com/?submit.750226
- https://www.tenda.com.cn/
