The remote host is missing an update to xpdf announced via advisory DSA 1347-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201347-1

It was discovered that an integer overflow in the xpdf PDF viewer may lead to the execution of arbitrary code if a malformed PDF file is opened. For the oldstable distribution (sarge) this problem has been fixed in version 3.00-13.7. For the stable distribution (etch) this problem has been fixed in version 3.01-9etch1. For the unstable distribution (sid) this problem will be fixed soon. We recommend that you upgrade your xpdf packages.