The remote host is missing an update to gpdf announced via advisory DSA 1136-1. infamous41md and Chris Evans discovered several heap based buffer overflows in xpdf, the Portable Document Format (PDF) suite, which are also present in gpdf, the viewer with Gtk bindings, and which can lead to a denial of service by crashing the application or possibly to the execution of arbitrary code.
For the stable distribution (sarge) these problems have been fixed in version 2.8.2-1.2sarge5. For the unstable distribution (sid) these problems have been fixed in version 2.10.0-4. We recommend that you upgrade your gpdf package. https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201136-1