CVE-2021-43636
📋 TL;DR
This CVE describes two buffer overflow vulnerabilities in T10 V2_Firmware's HTTP request parser that allow attackers to execute arbitrary code or crash the device. The vulnerabilities affect T10 V2_Firmware version 4.1.8cu.5207_B20210320 when processing host data in HTTP requests. Attackers can exploit these vulnerabilities remotely without authentication.
💻 Affected Systems
- T10 V2_Firmware
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, data theft, and potential lateral movement within the network.
Likely Case
Device crash (denial of service) or limited code execution depending on exploit sophistication.
If Mitigated
No impact if device is patched or network segmentation prevents access to vulnerable service.
🎯 Exploit Status
Buffer overflow vulnerabilities in HTTP parsing are typically straightforward to exploit once details are known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Later versions than V4.1.8cu.5207_B20210320
Vendor Advisory: https://note.youdao.com/s/918vCBNT
Restart Required: Yes
Instructions:
1. Check current firmware version. 2. Download latest firmware from vendor. 3. Apply firmware update following vendor instructions. 4. Reboot device. 5. Verify updated version is running.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected devices from untrusted networks and limit access to HTTP services.
Disable HTTP Service
allTurn off HTTP services if not required for device functionality.
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure
- Monitor for unusual HTTP traffic patterns and connection attempts
🔍 How to Verify
Check if Vulnerable:
Check firmware version via device web interface or CLI: version should be V4.1.8cu.5207_B20210320Check Version:
Check device web interface or use vendor-specific CLI command for version informationVerify Fix Applied:
Verify firmware version is newer than V4.1.8cu.5207_B20210320📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests with malformed host headers
- Device crash/restart logs
- Memory access violation errors
Network Indicators:
- HTTP requests with unusually long host headers
- Multiple connection attempts to device HTTP port
SIEM Query:
source_ip="*" AND dest_port=80 AND http_host_length>1000