If you've got Solaris with telnet running, you could be in for a big surprise. There is a fairly trivial Solaris telnet 0-day exploit in the wild [.pdf]. "This was posted to Full-Disclosure. Remote root exploit in the Solaris 10/11 telnet daemon. It doesn't require any skill, any exploit knowledge, and can be scripted for mass attacks. Basically if you pass a '-fusername' as an argument to the –l option you get full access to the OS as the user specified. In my example I do it as bin but it worked for regular users, just not for root. This combined with a reliable local privilege escalation exploit would be devastating. Expect mass scanning and possibly the widespread exploitation of this vulnerability."