CVE-2021-37933
📋 TL;DR
This LDAP injection vulnerability in Huntflow Enterprise allows unauthenticated remote attackers to bypass authentication by manipulating the email parameter in login requests. Attackers can use wildcard characters to modify LDAP query logic and gain unauthorized access. All Huntflow Enterprise instances before version 3.10.6 are affected.
💻 Affected Systems
- Huntflow Enterprise
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through unauthorized administrative access, leading to data theft, privilege escalation, and lateral movement within the network.
Likely Case
Unauthorized access to sensitive applicant tracking data, potential exposure of personally identifiable information (PII), and manipulation of recruitment processes.
If Mitigated
Authentication bypass attempts are detected and blocked, with no successful unauthorized access achieved.
🎯 Exploit Status
Exploitation requires valid password knowledge but uses wildcard characters in email field to bypass authentication checks.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.10.6
Vendor Advisory: https://gist.github.com/andrey-lomtev/cbf12bc8d8763996cf8d6d1641a0b049
Restart Required: Yes
Instructions:
1. Backup current Huntflow Enterprise installation. 2. Download version 3.10.6 or later from official vendor sources. 3. Follow vendor upgrade procedures. 4. Restart Huntflow Enterprise services. 5. Verify successful upgrade and test authentication functionality.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side validation to reject login attempts containing wildcard characters (*, ?, %, etc.) in the email parameter.
Implement input sanitization in /account/login endpoint to filter: *, ?, %, (, ), |, &, ;, =, +, -, <, >, "', \
WAF Rule
allConfigure web application firewall to block LDAP injection patterns in login requests.
Add WAF rule to block requests with LDAP metacharacters in email parameter: ^.*[\*\?%\(\)\|&;=+\-<>"'\\].*$
🧯 If You Can't Patch
- Implement network segmentation to restrict access to Huntflow Enterprise login endpoint only to authorized IP ranges.
- Enable detailed logging and monitoring of all authentication attempts with alerting for failed login patterns containing special characters.
🔍 How to Verify
Check if Vulnerable:
Test login endpoint with email parameter containing wildcard characters (e.g., *@domain.com) and a known valid password. If authentication succeeds, system is vulnerable.Check Version:
Check Huntflow Enterprise admin interface or configuration files for version number. Command varies by deployment method.Verify Fix Applied:
Attempt the same test with wildcard characters after patching. Authentication should fail with proper input validation errors.📡 Detection & Monitoring
Log Indicators:
- Login attempts with special characters in email field
- Successful authentication from unusual patterns
- Multiple failed login attempts with wildcard variations
Network Indicators:
- HTTP POST requests to /account/login with LDAP metacharacters in parameters
- Unusual authentication traffic patterns
SIEM Query:
source="huntflow_logs" AND (email="*" OR email="%" OR email="?" OR email CONTAINS "(" OR email CONTAINS ")") AND action="login"