CVE-2019-20431
📋 TL;DR
This vulnerability in the Lustre file system allows remote attackers to trigger out-of-bounds memory access and system panic by sending specially crafted packets. It affects Lustre installations before version 2.12.3 where the ptlrpc and osd_ldiskfs modules lack proper validation of packet fields.
💻 Affected Systems
- Lustre File System
📦 What is this software?
Lustre by Lustre
⚠️ Risk & Real-World Impact
Worst Case
Remote unauthenticated attacker causes kernel panic leading to complete system crash and denial of service
Likely Case
System instability and crashes affecting Lustre cluster availability
If Mitigated
Limited impact with proper network segmentation and access controls
🎯 Exploit Status
Exploitation requires network access to Lustre services and knowledge of protocol
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.12.3 and later
Vendor Advisory: http://wiki.lustre.org/Lustre_2.12.3_Changelog
Restart Required: Yes
Instructions:
1. Backup Lustre configuration and data
2. Stop Lustre services on all nodes
3. Upgrade to Lustre 2.12.3 or later
4. Restart Lustre services
5. Verify cluster functionality
🔧 Temporary Workarounds
Network Segmentation
linuxRestrict access to Lustre services to trusted clients only
iptables -A INPUT -p tcp --dport 988 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 988 -j DROP
🧯 If You Can't Patch
- Implement strict network access controls to Lustre services
- Monitor for abnormal client behavior and connection attempts
🔍 How to Verify
Check if Vulnerable:
Check Lustre version with 'lctl get_param version' and compare to 2.12.3Check Version:
lctl get_param version | grep -i lustreVerify Fix Applied:
Verify version is 2.12.3 or later and test cluster functionality📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- Lustre service crashes
- OOM errors in system logs
Network Indicators:
- Unusual packet patterns to Lustre ports
- Multiple connection attempts from single source
SIEM Query:
source="lustre.logs" AND ("panic" OR "crash" OR "out of bounds")