CVE-2024-4126
📋 TL;DR
This critical vulnerability in Tenda W15E routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the formSetSysTime function. Attackers can exploit this by sending specially crafted requests to the /goform/SetSysTimeCfg endpoint. Organizations and individuals using affected Tenda W15E routers are at risk.
💻 Affected Systems
- Tenda W15E
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise leading to persistent backdoor installation, credential theft, and use as pivot point for network attacks.
Likely Case
Remote code execution allowing attackers to take control of the router, modify configurations, intercept traffic, and launch further attacks.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Exploit code is publicly available on GitHub. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates 2. If update available, download and install via web interface 3. Reboot router after update 4. Verify firmware version changed from 15.11.0.14
🔧 Temporary Workarounds
Block vulnerable endpoint
linuxUse firewall rules to block access to /goform/SetSysTimeCfg endpoint
iptables -A INPUT -p tcp --dport 80 -m string --string "/goform/SetSysTimeCfg" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/goform/SetSysTimeCfg" --algo bm -j DROP
Disable remote management
allTurn off remote administration features in router settings
🧯 If You Can't Patch
- Replace affected Tenda W15E routers with different models or brands
- Isolate vulnerable routers in separate VLAN with strict firewall rules
🔍 How to Verify
Check if Vulnerable:
Check router web interface for firmware version. If version is 15.11.0.14, device is vulnerable.Check Version:
curl -s http://router-ip/login/Auth | grep firmware version or check web interfaceVerify Fix Applied:
Verify firmware version has changed from 15.11.0.14. Test if /goform/SetSysTimeCfg endpoint still responds.📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/SetSysTimeCfg
- Unusual payload sizes in HTTP requests
- Router crash/reboot logs
Network Indicators:
- HTTP POST requests to /goform/SetSysTimeCfg with large manualTime parameter
- Unusual outbound connections from router
SIEM Query:
source="router_logs" AND (url="/goform/SetSysTimeCfg" OR message="buffer overflow" OR message="crash")🔗 References
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/W15Ev1.0/formSetSysTime.md
- https://vuldb.com/?ctiid.261869
- https://vuldb.com/?id.261869
- https://vuldb.com/?submit.317831
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/W15Ev1.0/formSetSysTime.md
- https://vuldb.com/?ctiid.261869
- https://vuldb.com/?id.261869
- https://vuldb.com/?submit.317831
