The remote host is missing an update to xpdf announced via advisory DSA 619-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20619-1

An iDEFENSE security researcher discovered a buffer overflow in xpdf, the portable document format (PDF) suite. A maliciously crafted PDF file could exploit this problem, resulting in the execution of arbitrary code. For the stable distribution (woody) this problem has been fixed in version 1.00-3.3. For the unstable distribution (sid) this problem has been fixed in version 3.00-11. We recommend that you upgrade your xdpf package immediately.