MikroTik Advisory – Brute Force WinBox Vulnerability

Different routers have different feature sets and management interfaces, though security remains paramount. Brute Force attacks are one of the most common router vulnerabilities. This is very relevant to MikroTik users, since by default a MikroTik router will allow all traffic unless a specific firewall rule prevents the communication. It is important to take proper security steps to protect your routers.

In February, 2025, a vulnerability was identified in the WinBox service where a discrepancy in response size between connection attempts with valid and invalid usernames allows attackers to confirm if a user account exists via brute forcing the login process. In other words, when an attacker tries to log into the device, by examining the response, the attacker can deduce if such a user exists on the device. Even if the username is found, the password still needs to be guessed as well.

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👉 Affected Versions

RouterOS versions prior to 6.49.18 and 7.18.

🛠 Recommended Actions

✅ Update RouterOS – Upgrade to 6.49.18, 7.18, or a newer version to patch the vulnerability.

✅ Monitor for unusual login attempts – Review router logs for suspicious authentication activity and take action accordingly.

✅ Utilize Admiral Platform. If you have a few potentially affected routers to update, Admiral’s firmware manager can help display all current router firmware and makes mass firmware updating easier.

💡 Some additional great security resources:

✅ Read up on how to remove your default admin account, creating your own user, and updating to strong passwords.

🎥 Watch Firewall Best Practices video

✅  Read Firewall tips and tricks specific to brute force login protection:

Brute Force Login Protection Tips