The remote host is missing an update to emacs20 announced via advisory DSA 670-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20670-1

Max Vozeler discovered several format string vulnerabilities in the movemail utility of Emacs, the well-known editor. Via connecting to a malicious POP server an attacker can execute arbitrary code under the privileges of group mail. For the stable distribution (woody) these problems have been fixed in version 20.7-13.3. The unstable distribution (sid) does not contain an Emacs20 package anymore. We recommend that you upgrade your emacs packages.