The remote host is missing an update to xpdf announced via advisory DSA 1790-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201790-1

Several vulnerabilities have been identified in xpdf, a suite of tools for viewing and converting Portable Document Format (PDF) files. For details on the issues addressed with this update, please visit the referenced security advisories. For the old stable distribution (etch), these problems have been fixed in version 3.01-9.1+etch6. For the stable distribution (lenny), these problems have been fixed in version 3.02-1.4+lenny1. For the unstable distribution (sid), these problems will be fixed in a forthcoming version. We recommend that you upgrade your xpdf packages.