The remote host is missing an update to emacs21 announced via advisory USN-76-1.
Max Vozeler discovered a format string vulnerability in the 'movemail' utility of Emacs. By sending specially crafted packets, a malicious POP3 server could cause a buffer overflow, which could have been exploited to execute arbitrary code with the privileges of the user and the 'mail' group (since 'movemail' is installed as 'setgid mail').
The following packages are affected: emacs21-bin-common
Solution: The problem can be corrected by upgrading the affected package to version 21.3+1-5ubuntu4.2. In general, a standard system upgrade is sufficient to effect the necessary changes.