The remote host is missing an update to xfree86 announced via advisory DSA 607-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20607-1

Several developers have discovered a number of problems in the libXpm library which is provided by X.Org, XFree86 and LessTif. These bugs can be exploited by remote and/or local attackers to gain access to the system or to escalate their local privileges, by using a specially crafted XPM image. For the stable distribution (woody) this problem has been fixed in version 4.1.0-16woody5. For the unstable distribution (sid) this problem will be fixed in version 4.3.0.dfsg.1-9. We recommend that you upgrade your libxpm package immediately.