CVE-2022-3116
📋 TL;DR
CVE-2022-3116 is a null pointer dereference vulnerability in Heimdal Kerberos 5 implementation. Attackers with network access to applications using vulnerable Heimdal code can cause denial of service crashes. This affects systems running Heimdal Kerberos or applications that depend on it.
💻 Affected Systems
- Heimdal Kerberos 5
📦 What is this software?
Heimdal by Heimdal Project
⚠️ Risk & Real-World Impact
Worst Case
Critical applications relying on Heimdal Kerberos crash, causing widespread service disruption and potential cascading failures in dependent systems.
Likely Case
Targeted applications crash, resulting in denial of service for affected services until restarted.
If Mitigated
Minimal impact with proper network segmentation and monitoring allowing quick detection and recovery.
🎯 Exploit Status
Exploitation requires network access to vulnerable service but no authentication. The vulnerability is triggered through specific network packets.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Heimdal 7.7.1 and later
Vendor Advisory: https://github.com/heimdal/heimdal/releases/tag/heimdal-7.7.1
Restart Required: Yes
Instructions:
1. Check current Heimdal version. 2. Update to Heimdal 7.7.1 or later using package manager. 3. Restart affected services using Heimdal Kerberos.
🔧 Temporary Workarounds
Network segmentation
allRestrict network access to services using Heimdal Kerberos to trusted sources only
Service monitoring and auto-restart
linuxImplement monitoring and automatic restart for vulnerable services
systemctl enable --now vulnerable-service
Configure monitoring to restart on crash
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure
- Deploy monitoring with alerting for service crashes and unusual Kerberos traffic
🔍 How to Verify
Check if Vulnerable:
Check Heimdal version: krb5-config --version or check installed packages for heimdal versionCheck Version:
krb5-config --version 2>/dev/null || dpkg -l | grep heimdal || rpm -qa | grep heimdalVerify Fix Applied:
Verify version is 7.7.1 or later: krb5-config --version | grep -q '7\.7\.1\|7\.[8-9]\|7\.[1-9][0-9]\|[8-9]\.[0-9]'📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation fault
- Kerberos service termination
- Core dumps from Heimdal processes
Network Indicators:
- Unusual Kerberos traffic patterns
- Connection attempts to Kerberos ports from untrusted sources
SIEM Query:
source="*kerberos*" AND (event="segmentation fault" OR event="core dumped" OR event="crash")