Introduction
The Terrapin attack is a cryptographic attack on the commonly used SSH protocol that is used for secure command-and-control throughout the Internet. The Terrapin attack can reduce the security of ssh by using a downgrade attack via man-in-the-middle interception. SSH is an internet standard that provides secure access to network services, particularly remote terminal login and file transfer within organizational networks and to over 15 million servers on the open internet. Terrapin is a prefix truncation attack targeting the SSH protocol. More precisely, Terrapin breaks the integrity of SSH's secure channel. By carefully adjusting the sequence numbers during the handshake, an attacker can remove an arbitrary amount of messages sent by the client or server at the beginning of the secure channel without the client or server noticing it. More about the Terrapin attack at: https://terrapin-attack.com/ Terrapin Vulnerability Scanner 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. Head over to Github for the Terrapin scanner https://github.com/RUB-NDS/Terrapin-Scanner/releases/tag/v1.1.0. where you will find versions for Linux, Windows and Mac platforms. |