CVE-2025-55498
📋 TL;DR
This buffer overflow vulnerability in Tenda AC6 routers allows attackers to execute arbitrary code by sending specially crafted requests to the time parameter in the fromSetSysTime function. Attackers could potentially gain full control of affected routers. This affects users of Tenda AC6 routers running vulnerable firmware versions.
💻 Affected Systems
- Tenda AC6
📦 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, create persistent backdoors, or pivot to internal networks.
Likely Case
Router crash/reboot causing denial of service, or limited code execution allowing network reconnaissance and potential lateral movement.
If Mitigated
No impact if routers are not internet-facing and network segmentation prevents access to management interfaces.
🎯 Exploit Status
Proof-of-concept code is publicly available on GitHub. Exploitation requires sending HTTP request to vulnerable endpoint with crafted time parameter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None known
Restart Required: Yes
Instructions:
1. Check Tenda support site for firmware updates. 2. Download latest firmware for AC6 model. 3. Access router web interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload new firmware file. 6. Wait for router to reboot.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Access router web interface > Advanced > System Tools > Remote Management > Disable
Network Segmentation
allIsolate router management interface to trusted network
Configure firewall rules to restrict access to router IP on ports 80/443 to trusted IPs only
🧯 If You Can't Patch
- Replace vulnerable routers with different models from vendors with better security track record
- Implement network monitoring to detect exploitation attempts and isolate compromised devices
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface under System Status or via command: telnet [router_ip] (if enabled) and check versionCheck Version:
curl -s http://[router_ip]/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version is newer than V15.03.06.23 and test if fromSetSysTime endpoint still exists📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to /goform/fromSetSysTime with malformed time parameter
- Router crash/reboot logs
- Unusual process execution
Network Indicators:
- HTTP traffic to router IP on port 80/443 with POST to /goform/fromSetSysTime
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND (uri="/goform/fromSetSysTime" OR "fromSetSysTime")