When it comes to ensuring the security of your server, checking for user accounts with weak passwords is crucial. To accomplish this task, one of the most effective tools you can use is a password auditing tool such as John the Ripper or L0phtCrack.

John the Ripper is a fast password cracker, currently available for many flavors of Unix, Windows, DOS, and OpenVMS. It can be used to detect weak passwords, improve password strength, and more.

L0phtCrack, on the other hand, is a password auditing and recovery application designed to test password strength and recover lost Microsoft Windows passwords. It can also be used to identify weak passwords and improve overall security.

By utilizing these tools, you can proactively identify and address any vulnerabilities in your server's user accounts, thereby enhancing your overall cybersecurity posture.