The remote host is missing an update to xpdf announced via advisory DSA 1548-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201548-1

Kees Cook discovered a vulnerability in xpdf, set set of tools for display and conversion of Portable Document Format (PDF) files. The Common Vulnerabilities and Exposures project identifies the following problem: CVE-2008-1693 Xpdf's handling of embedded fonts lacks sufficient validation and type checking. If a maliciously-crafted PDF file is opened, the vulnerability may allow the execution of arbitrary code with the privileges of the user running xpdf. For the stable distribution (etch), these problems have been fixed in version 3.01-9.1+etch3. For the unstable distribution (sid), these problems were fixed in version 3.02-1.2. We recommend that you upgrade your xpdf package.