CVE-2024-4252
📋 TL;DR
This critical vulnerability in Tenda i22 routers allows remote attackers to execute arbitrary code via a stack-based buffer overflow in the formSetUrlFilterRule function. Attackers can exploit this by manipulating the groupIndex argument, potentially gaining full control of affected devices. All users running Tenda i22 firmware version 1.0.0.3(4687) are affected.
💻 Affected Systems
- Tenda i22
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, persistent backdoor installation, network traffic interception, and lateral movement to other network devices.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as part of a botnet.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 Exploit Status
Public proof-of-concept code exists in GitHub repositories. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available - vendor did not respond to disclosure
Restart Required: Yes
Instructions:
No official patch available. Check Tenda website for firmware updates. If available, download latest firmware, access router admin interface, navigate to firmware upgrade section, upload new firmware, and reboot.
🔧 Temporary Workarounds
Disable Remote Management
allDisable web management interface access from WAN/Internet to prevent remote exploitation
Access router admin interface -> System Tools -> Remote Management -> Disable
Network Segmentation
allIsolate Tenda i22 devices in separate VLAN with restricted access
🧯 If You Can't Patch
- Replace affected Tenda i22 routers with different models from vendors with better security track records
- Implement strict network access controls to limit traffic to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface: System Status -> Firmware Version. If version is 1.0.0.3(4687), device is vulnerable.Check Version:
Check via web interface or attempt to connect to router admin page and inspect versionVerify Fix Applied:
Verify firmware version has changed from 1.0.0.3(4687) to a newer version after update.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to formSetUrlFilterRule endpoint
- Multiple failed buffer overflow attempts
- Sudden configuration changes
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns suggesting device compromise
- Exploit kit traffic targeting router management ports
SIEM Query:
source="router_logs" AND (uri="*/goform/setUrlFilterRule" OR message="*buffer overflow*" OR message="*formSetUrlFilterRule*")🔗 References
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/i/i22/formSetUrlFilterRule.md
- https://vuldb.com/?ctiid.262143
- https://vuldb.com/?id.262143
- https://vuldb.com/?submit.319840
- https://github.com/abcdefg-png/IoT-vulnerable/blob/main/Tenda/i/i22/formSetUrlFilterRule.md
- https://vuldb.com/?ctiid.262143
- https://vuldb.com/?id.262143
- https://vuldb.com/?submit.319840
