The remote host is missing an update to sudo announced via advisory DSA 128-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20128-1

fc found a buffer overflow in the variable expansion code used by sudo for its prompt. Since sudo is necessarily installed suid root a local user can use this to gain root access. This has been fixed in version 1.6.2-2.2 and we recommend that you upgrade