The key can contain numbers, letters, or symbols like the one above. On remote Unix, Linux, or macOS machines the public key needs to be placed into a file called ~/.ssh/authorized_keys file using a ...

It affects only keys using the RSA cryptographic algorithm, which the researchers found in roughly a third of the SSH signatures they examined.

Cisco has released security updates to address critical security flaws allowing unauthenticated attackers to log in using hard-coded credentials or default SSH keys to take over unpatched devices.