After a server was compromised an incident responder looks at log files to determine the...

The logs indicate a directory traversal attempt (/../..//.etc/shadow), which is a type of attack that exploits insufficient security validation/sanitization of user-supplied input file names, so that characters representing "traverse to parent directory" are passed through to the file APIs. The /etc/shadow file on Unix systems contains password hashes. If an attacker successfully exploited this vulnerability, they could potentially access the hashed SSH password. This information could then be used to gain unauthorized access to the server if the hash was cracked.