CVE-2024-4493
📋 TL;DR
A critical stack-based buffer overflow vulnerability in Tenda i21 routers allows remote attackers to execute arbitrary code by manipulating ping parameters in the formSetAutoPing function. This affects Tenda i21 router version 1.0.0.14(4656) and potentially other versions. Attackers can exploit this without authentication to take full control of affected devices.
💻 Affected Systems
- Tenda i21 router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistence installation, network pivoting, and data exfiltration.
Likely Case
Router takeover enabling traffic interception, DNS manipulation, credential theft, and botnet recruitment.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit code available on GitHub. Remote exploitation requires no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None - vendor did not respond to disclosure
Restart Required: Yes
Instructions:
No official patch available. Consider replacing affected devices or implementing workarounds.
🔧 Temporary Workarounds
Network segmentation and isolation
allPlace affected routers in isolated network segments with strict firewall rules
Disable remote management
allEnsure router web interface is not accessible from the internet
🧯 If You Can't Patch
- Replace affected Tenda i21 routers with different models from vendors with better security practices
- Implement strict network monitoring and anomaly detection for router traffic patterns
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at http://router_ip/status.asp or http://router_ip/goform/getStatusCheck Version:
curl -s http://router_ip/status.asp | grep -i versionVerify Fix Applied:
No fix available to verify. Monitor for firmware updates from Tenda.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/formSetAutoPing with long ping parameters
- Router reboot events
- Unusual outbound connections from router
Network Indicators:
- HTTP requests with abnormally long ping1/ping2 parameters to router management interface
- Sudden changes in router DNS settings
- Unusual traffic patterns from router IP
SIEM Query:
source="router_logs" AND (url="/goform/formSetAutoPing" AND (param_length>100 OR contains(param,"ping1") OR contains(param,"ping2")))🔗 References
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/i/i21/formSetAutoPing.md
- https://vuldb.com/?ctiid.263082
- https://vuldb.com/?id.263082
- https://vuldb.com/?submit.323602
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/i/i21/formSetAutoPing.md
- https://vuldb.com/?ctiid.263082
- https://vuldb.com/?id.263082
- https://vuldb.com/?submit.323602
