CVE-2022-31802
📋 TL;DR
CVE-2022-31802 is an authentication bypass vulnerability in CODESYS Gateway Server V2 where only a portion of the password is validated. Attackers can authenticate by providing a short password that matches the beginning of the actual password. This affects CODESYS Gateway Server V2 versions prior to V2.3.9.38.
💻 Affected Systems
- CODESYS Gateway Server V2
📦 What is this software?
Gateway by Codesys
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial control systems, allowing attackers to modify PLC logic, disrupt operations, or cause physical damage.
Likely Case
Unauthorized access to industrial networks, data theft, manipulation of industrial processes, and lateral movement to other systems.
If Mitigated
Limited impact if strong network segmentation, monitoring, and additional authentication layers are in place.
🎯 Exploit Status
Exploitation requires network access to the Gateway Server but authentication is bypassed. No public exploit code is known, but the vulnerability is simple to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V2.3.9.38
Vendor Advisory: https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=17141&token=17867e35cfd30c77ba0137f9a17b3a557a4b7b66&download=
Restart Required: Yes
Instructions:
1. Download CODESYS Gateway Server V2 version 2.3.9.38 or later from the CODESYS website. 2. Stop the CODESYS Gateway service. 3. Install the update. 4. Restart the service.
🔧 Temporary Workarounds
Network Segmentation
allIsolate CODESYS Gateway Server from untrusted networks and internet.
Disable Password Authentication
allUse certificate-based authentication instead of password authentication if supported.
🧯 If You Can't Patch
- Implement strict network access controls to limit connections to trusted IP addresses only.
- Enable detailed logging and monitoring for authentication attempts and implement alerting for failed/suspicious logins.
🔍 How to Verify
Check if Vulnerable:
Check the CODESYS Gateway Server version in the administration interface or via the installed software list.Check Version:
On Windows: Check Programs and Features. On Linux: Check package manager or run 'codesys-gateway --version' if available.Verify Fix Applied:
Verify the version is 2.3.9.38 or higher and test authentication with partial passwords to confirm they are rejected.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful login with short passwords
- Authentication logs showing successful logins from unexpected sources
Network Indicators:
- Unusual network traffic to CODESYS Gateway port (typically 1217/TCP)
- Authentication attempts with short password strings
SIEM Query:
source="codesys_gateway.log" AND (event="authentication_success" AND password_length<8) OR (event="authentication_failure" AND password_length<8)