CVE-2024-22778
📋 TL;DR
CVE-2024-22778 is a Denial of Service vulnerability in HackMD CodiMD that allows attackers to crash the service, making it unavailable to legitimate users. This affects all organizations running vulnerable versions of CodiMD for collaborative markdown editing. The vulnerability requires no authentication to exploit.
💻 Affected Systems
- HackMD CodiMD
📦 What is this software?
Codimd by Hackmd
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage of CodiMD instance, disrupting all collaborative document editing and potentially causing data loss for unsaved work.
Likely Case
Temporary service disruption requiring manual restart of the CodiMD application, causing productivity loss for teams relying on the platform.
If Mitigated
Minimal impact with proper monitoring and automated recovery systems in place to detect and restart crashed services.
🎯 Exploit Status
The vulnerability appears to be triggered via specific HTTP requests that cause resource exhaustion or application crashes.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.5.2
Vendor Advisory: https://github.com/hackmdio/codimd/issues/1846
Restart Required: Yes
Instructions:
1. Backup your CodiMD data and configuration. 2. Update to CodiMD version 2.5.2 or later using npm update or package manager. 3. Restart the CodiMD service. 4. Verify the update was successful.
🔧 Temporary Workarounds
Rate Limiting
allImplement rate limiting on HTTP requests to reduce the impact of DoS attempts
# Configure rate limiting in your reverse proxy (nginx example)
limit_req_zone $binary_remote_addr zone=codimd:10m rate=10r/s;
limit_req zone=codimd burst=20 nodelay;
Network Segmentation
linuxRestrict access to CodiMD to trusted networks only
# Firewall rule example (iptables)
iptables -A INPUT -p tcp --dport 3000 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 3000 -j DROP
🧯 If You Can't Patch
- Implement aggressive rate limiting and request filtering at the network perimeter
- Deploy monitoring with automated restart scripts to detect and recover from crashes
🔍 How to Verify
Check if Vulnerable:
Check CodiMD version via web interface or by examining package.json fileCheck Version:
npm list codimd | grep codimdVerify Fix Applied:
Confirm version is 2.5.2 or higher and test service stability under normal load📡 Detection & Monitoring
Log Indicators:
- Sudden service crashes
- High CPU/memory usage spikes
- Repeated failed requests from single IPs
Network Indicators:
- Unusual HTTP request patterns
- High volume of requests to specific endpoints
SIEM Query:
source="codimd.log" AND ("crash" OR "restart" OR "out of memory")