This guide by user Manual Nader will show you how to fingerprint different FreeBSD versions with OpenSSH. The idea is to translate the banner’s ID into its corresponding OS version. See the link below for a further explanation of FreeBSD banners and FreeBSD versions.

In the past, we’ve described how to fingerprint Ubuntu OS Version using OpenSSH. This time, I’ll explain how to Fingerprint FreeBSD.

The basic theory is the same:

  1. We’ll grab the Banner from the SSH port (usually port 22)
  2. Determine if it’s an OpenSSH banner
  3. Map out the SSH Comment to a list of banners we have and determine the FreeBSD version.

The big difference from the Ubuntu post is how to map the FreeBSD banners. I’ll explain that next.

Fingerprinting FreeBSD OS Versions using OpenSSH: