CVE-2024-8418
📋 TL;DR
CVE-2024-8418 is a denial-of-service vulnerability in Aardvark-dns where an attacker can keep TCP connections open indefinitely, causing the DNS server to become unresponsive. This prevents legitimate DNS queries from being processed, disrupting DNS services. Organizations using Aardvark-dns for container networking are affected.
💻 Affected Systems
- Aardvark-dns
📦 What is this software?
Aardvark Dns by Containers
Aardvark Dns by Containers
⚠️ Risk & Real-World Impact
Worst Case
Complete DNS service outage for all containers relying on Aardvark-dns, causing application failures and service disruption across containerized environments.
Likely Case
Intermittent DNS resolution failures and increased latency for container applications, potentially causing timeouts and degraded performance.
If Mitigated
Minimal impact with proper network segmentation and connection limits, though some performance degradation may still occur during attacks.
🎯 Exploit Status
Exploitation requires network access to the Aardvark-dns service and ability to establish TCP connections. The attack is simple to execute with basic networking tools.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in Aardvark-dns versions with the fix from pull request #503
Vendor Advisory: https://access.redhat.com/security/cve/CVE-2024-8418
Restart Required: Yes
Instructions:
1. Update Aardvark-dns to the patched version. 2. Restart the Aardvark-dns service. 3. For container environments, ensure container runtimes are using the updated version.
🔧 Temporary Workarounds
Implement TCP connection limits
linuxUse system firewall rules to limit TCP connections to the Aardvark-dns service
iptables -A INPUT -p tcp --dport 53 -m connlimit --connlimit-above 10 --connlimit-mask 32 -j REJECT
Use UDP-only mode
allConfigure applications to use UDP DNS queries instead of TCP where possible
🧯 If You Can't Patch
- Implement network segmentation to isolate Aardvark-dns from untrusted networks
- Monitor for excessive TCP connections to DNS service and implement rate limiting
🔍 How to Verify
Check if Vulnerable:
Check Aardvark-dns version and compare against patched versions mentioned in advisoryCheck Version:
aardvark-dns --version or check container runtime configurationVerify Fix Applied:
Verify Aardvark-dns is updated to version containing fix from PR #503 and test TCP DNS query handling📡 Detection & Monitoring
Log Indicators:
- Excessive TCP connections to port 53
- DNS query timeouts
- Aardvark-dns process becoming unresponsive
Network Indicators:
- Multiple long-lived TCP connections to DNS port from single source
- Increased DNS response times
SIEM Query:
source_port=53 AND protocol=TCP | stats count by src_ip | where count > threshold