CVE-2024-4497
📋 TL;DR
This critical vulnerability in Tenda i21 routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the formexeCommand function. Attackers can exploit this without authentication to potentially take full control of affected devices. All users running vulnerable firmware versions are at risk.
💻 Affected Systems
- Tenda i21
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify device configuration, steal credentials, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public exploit details are available on GitHub, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
No official patch available. Contact Tenda support for firmware updates. If unavailable, replace affected devices.
🔧 Temporary Workarounds
Network Isolation
allPlace affected routers behind firewalls with strict inbound filtering
Access Control
allRestrict administrative access to trusted IP addresses only
🧯 If You Can't Patch
- Immediately disconnect vulnerable devices from the internet
- Replace affected routers with patched or alternative devices
🔍 How to Verify
Check if Vulnerable:
Check router web interface or CLI for firmware version 1.0.0.14(4656)Check Version:
Check router web interface at http://[router-ip]/ or use telnet/ssh if enabledVerify Fix Applied:
Verify firmware version has been updated to a version later than 1.0.0.14(4656)📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to formexeCommand endpoint
- Large payloads in HTTP requests
- Unexpected device reboots or configuration changes
Network Indicators:
- Unusual outbound connections from router
- Traffic spikes to/from router management interface
- Exploit-specific payload patterns in network traffic
SIEM Query:
source="router_logs" AND (uri="*formexeCommand*" OR data_size>1000) OR event="buffer_overflow"🔗 References
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/i/i21/formexeCommand.md
- https://vuldb.com/?ctiid.263086
- https://vuldb.com/?id.263086
- https://vuldb.com/?submit.323607
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/i/i21/formexeCommand.md
- https://vuldb.com/?ctiid.263086
- https://vuldb.com/?id.263086
- https://vuldb.com/?submit.323607
