CVE-2021-32286
📋 TL;DR
CVE-2021-32286 is a critical buffer overflow vulnerability in hcxtools that allows remote code execution when processing malicious pcapng files. Attackers can exploit this by tricking users into opening specially crafted packet capture files. This affects all users of hcxtools versions through 6.1.6.
💻 Affected Systems
- hcxtools
📦 What is this software?
Hcxtoold by Hcxtools Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining root privileges and persistent access to the system.
Likely Case
Local privilege escalation or remote code execution when processing untrusted pcapng files.
If Mitigated
Denial of service or application crash if exploit fails or is blocked by security controls.
🎯 Exploit Status
Proof of concept available in GitHub issue #155. Exploitation requires user to process malicious pcapng file.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.1.7 and later
Vendor Advisory: https://github.com/ZerBea/hcxtools/issues/155
Restart Required: No
Instructions:
1. Update hcxtools to version 6.1.7 or later using package manager. 2. For manual installation: git clone repository, build with make, install with sudo make install.
🔧 Temporary Workarounds
Restrict pcapng file processing
linuxLimit hcxtools execution to trusted users and restrict processing of untrusted pcapng files.
chmod 750 /usr/bin/hcxpcapngtool
setfacl -m u:trusteduser:rx /usr/bin/hcxpcapngtool
🧯 If You Can't Patch
- Remove hcxtools from production systems if not essential
- Implement strict file validation and sandboxing for pcapng processing
🔍 How to Verify
Check if Vulnerable:
Run: hcxpcapngtool --version | grep -q '6\.1\.[0-6]' && echo 'VULNERABLE'Check Version:
hcxpcapngtool --versionVerify Fix Applied:
Run: hcxpcapngtool --version | grep -q '6\.1\.[7-9]\|6\.[2-9]\|7\.[0-9]' && echo 'PATCHED'📡 Detection & Monitoring
Log Indicators:
- Segmentation fault errors in system logs
- Abnormal process termination of hcxpcapngtool
Network Indicators:
- Unexpected network connections after pcapng file processing
- Suspicious downloads of pcapng files
SIEM Query:
process_name='hcxpcapngtool' AND (event_type='segfault' OR exit_code=139)