CVE-2024-24199
📋 TL;DR
CVE-2024-24199 is a memory misalignment vulnerability in smartdns that could allow attackers to cause denial of service or potentially execute arbitrary code. This affects systems running smartdns with the vulnerable code. The vulnerability stems from improper memory alignment in DNS packet processing.
💻 Affected Systems
- smartdns
📦 What is this software?
Smartdns by Pymumu
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise
Likely Case
Denial of service causing smartdns to crash
If Mitigated
Limited impact if proper network segmentation and access controls are in place
🎯 Exploit Status
Exploitation requires sending specially crafted DNS packets to the vulnerable service
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit 54b4dc or later
Vendor Advisory: https://github.com/pymumu/smartdns/issues/1628
Restart Required: Yes
Instructions:
1. Update smartdns to commit 54b4dc or later
2. Rebuild from source if using source installation
3. Restart the smartdns service
🔧 Temporary Workarounds
Network segmentation
linuxRestrict access to smartdns service to trusted networks only
iptables -A INPUT -p tcp --dport 53 -s trusted_network -j ACCEPT
iptables -A INPUT -p udp --dport 53 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 53 -j DROP
iptables -A INPUT -p udp --dport 53 -j DROP
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure
- Monitor smartdns process health and restart automatically if crashes occur
🔍 How to Verify
Check if Vulnerable:
Check smartdns version or commit hash. If before commit 54b4dc, it's vulnerable.Check Version:
smartdns -vVerify Fix Applied:
Verify smartdns is running commit 54b4dc or later and test with normal DNS queries📡 Detection & Monitoring
Log Indicators:
- smartdns crash logs
- segmentation fault errors in system logs
- unexpected service restarts
Network Indicators:
- Unusual DNS traffic patterns
- Malformed DNS packets to port 53
SIEM Query:
source="smartdns.log" AND ("segmentation fault" OR "crash" OR "SIGSEGV")