nessus-core

Nessus allows scans for the following types of vulnerabilities: 

Vulnerabilities that allow a remote hacker to control or access sensitive data on a system.
Misconfiguration (e.g. open mail relay, missing patches, etc.).
Default passwords, a few common passwords, and blank/absent passwords on some system accounts.
Nessus can also call Hydra (an external tool) to launch a dictionary attack.
Denials of service against the TCP/IP stack by using mangled packets