CVE-2021-37934
📋 TL;DR
This vulnerability allows unauthenticated remote attackers to perform unlimited login attempts against Huntflow Enterprise's authentication endpoint, enabling brute-force password attacks. It affects all Huntflow Enterprise installations before version 3.10.14 that have the login functionality exposed.
💻 Affected Systems
- Huntflow Enterprise
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could brute-force administrator credentials, gain full system access, and compromise sensitive recruitment data including candidate information, internal communications, and organizational data.
Likely Case
Attackers would brute-force weaker user passwords, gain unauthorized access to user accounts, and potentially access sensitive candidate data and internal recruitment information.
If Mitigated
With proper rate limiting and account lockout policies, impact is limited to temporary service disruption from failed login attempts.
🎯 Exploit Status
Simple HTTP POST requests to /account/login endpoint with different credentials. Attack tools like Hydra or Burp Intruder can automate exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.10.14
Vendor Advisory: https://gist.github.com/andrey-lomtev/4ec9004101152ea9d0043a09d59498a6
Restart Required: Yes
Instructions:
1. Backup current installation and data. 2. Download Huntflow Enterprise version 3.10.14 or later from official sources. 3. Follow vendor upgrade documentation. 4. Restart the application service. 5. Verify the fix by testing login rate limiting.
🔧 Temporary Workarounds
Web Application Firewall (WAF) Rate Limiting
allConfigure WAF rules to limit login attempts per IP address and implement account lockout policies.
# Example nginx rate limiting:
limit_req_zone $binary_remote_addr zone=login:10m rate=5r/m;
location /account/login {
limit_req zone=login burst=10 nodelay;
}
Network Access Control
linuxRestrict access to /account/login endpoint to trusted IP ranges only.
# Example iptables rule:
iptables -A INPUT -p tcp --dport 443 -m string --string "/account/login" --algo bm -j DROP
🧯 If You Can't Patch
- Implement strong password policies requiring complex passwords to reduce brute-force success probability
- Enable multi-factor authentication (MFA) for all user accounts to prevent credential-based attacks
🔍 How to Verify
Check if Vulnerable:
Attempt more than 10 consecutive failed logins to /account/login endpoint from same IP. If no account lockout or rate limiting occurs, system is vulnerable.Check Version:
Check Huntflow Enterprise admin panel or configuration files for version number. Should be 3.10.14 or higher.Verify Fix Applied:
After patching, attempt multiple failed logins. System should implement account lockout or rate limiting after 5-10 attempts.📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts from same IP address
- Unusual login patterns outside business hours
- Rapid sequence of POST requests to /account/login
Network Indicators:
- High volume of HTTP 401/403 responses from login endpoint
- Unusual traffic patterns to authentication URLs
SIEM Query:
source="huntflow.logs" AND (url_path="/account/login" AND response_code=401) | stats count by src_ip | where count > 10