The Terrapin Vulnerability Scanner is a small utility program written in Go, which can be used to determine the vulnerability of an SSH client or server against the Terrapin Attack. The vulnerability scanner requires a single connection with the peer to gather all supported algorithms. However, it does not perform a fully fledged SSH key exchange, will never attempt authentication on a server, and does not perform the attack in practice. Instead, vulnerability is determined by checking the supported algorithms and support for known countermeasures (strict key exchange). This may falsely claim vulnerability in case the peer supports countermeasures unknown to this tool.