CVE-2024-31030
📋 TL;DR
A NULL pointer dereference vulnerability in FreeCoAP v0.7 allows remote attackers to cause denial of service or potentially disclose memory contents via specially crafted CoAP packets. This affects systems using FreeCoAP library for CoAP protocol implementation. The vulnerability is remotely exploitable without authentication.
💻 Affected Systems
- FreeCoAP
📦 What is this software?
Freecoap by Keith Cullen
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption through crash, potential memory disclosure revealing sensitive information, and possible remote code execution depending on memory layout.
Likely Case
Denial of service through application crash, with potential partial memory disclosure in error messages or crash dumps.
If Mitigated
Application restart with minimal data loss if proper monitoring and restart mechanisms are in place.
🎯 Exploit Status
The vulnerability requires sending specially crafted CoAP packets but does not require authentication or special privileges.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v0.8 or later
Vendor Advisory: https://github.com/keith-cullen/FreeCoAP/issues/36
Restart Required: Yes
Instructions:
1. Update FreeCoAP library to version 0.8 or later. 2. Recompile any applications using FreeCoAP. 3. Restart affected services.
🔧 Temporary Workarounds
Network filtering
linuxBlock or filter CoAP traffic (typically UDP port 5683) from untrusted sources
iptables -A INPUT -p udp --dport 5683 -j DROP
🧯 If You Can't Patch
- Implement network segmentation to isolate CoAP services from untrusted networks
- Deploy intrusion detection/prevention systems to detect and block malformed CoAP packets
🔍 How to Verify
Check if Vulnerable:
Check if FreeCoAP library version 0.7 is installed and linked by applicationsCheck Version:
Check library headers or build configuration for FreeCoAP versionVerify Fix Applied:
Verify FreeCoAP library version is 0.8 or later and applications have been recompiled📡 Detection & Monitoring
Log Indicators:
- Application crashes
- Segmentation fault errors
- Unexpected termination of CoAP services
Network Indicators:
- Malformed CoAP packets
- Unusual UDP traffic on port 5683
SIEM Query:
source="application.logs" AND ("segmentation fault" OR "null pointer" OR "FreeCoAP crash")