CVE-2025-5798
📋 TL;DR
A critical stack-based buffer overflow vulnerability in Tenda AC8 routers allows remote attackers to execute arbitrary code by manipulating the timeType parameter in the fromSetSysTime function. This affects Tenda AC8 routers running firmware version 16.03.34.09. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Tenda AC8
📦 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 allowing attackers to modify router settings, intercept network traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering, though internal threats could still exploit the vulnerability.
🎯 Exploit Status
Exploit details have been publicly disclosed, making weaponization highly probable. 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's official website for security advisories. 2. If a patch is released, download the firmware update. 3. Log into router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply the new firmware. 6. Reboot the router.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Tenda AC8 routers from critical network segments and restrict access to management interfaces.
Access Control Lists
linuxImplement firewall rules to block external access to router web interface (typically port 80/443).
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Replace affected routers with patched or alternative models
- Implement strict network segmentation to isolate vulnerable devices
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is exactly 16.03.34.09, the device is vulnerable.Check Version:
Login to router web interface and check System Status or Firmware Upgrade section for version information.Verify Fix Applied:
After updating, verify firmware version has changed from 16.03.34.09 to a newer version.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/SetSysTimeCfg
- Multiple failed exploitation attempts with malformed timeType parameters
- Unexpected router reboots or configuration changes
Network Indicators:
- Unusual outbound connections from router to unknown IPs
- Traffic patterns suggesting command and control communication
- Port scanning originating from router
SIEM Query:
source="router_logs" AND (uri="/goform/SetSysTimeCfg" OR (method="POST" AND uri CONTAINS "SetSysTime"))🔗 References
- https://lavender-bicycle-a5a.notion.site/Tenda-AC8-fromSetSysTime-20a53a41781f807b9489fff42f262e11?source=copy_link
- https://vuldb.com/?ctiid.311352
- https://vuldb.com/?id.311352
- https://vuldb.com/?submit.591266
- https://www.tenda.com.cn/
- https://lavender-bicycle-a5a.notion.site/Tenda-AC8-fromSetSysTime-20a53a41781f807b9489fff42f262e11
