The remote host is missing an update to libgd2 announced via advisory DSA 1613-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201613-1

Multiple vulnerabilities have been identified in libgd2, a library for programmatic graphics creation and manipulation. The Common Vulnerabilities and Exposures project identifies the following three issues: CVE-2007-2445 Grayscale PNG files containing invalid tRNS chunk CRC values could cause a denial of service (crash), if a maliciously crafted image is loaded into an application using libgd. CVE-2007-3476 An array indexing error in libgd's GIF handling could induce a denial of service (crash with heap corruption) if exceptionally large color index values are supplied in a maliciously crafted GIF image file. CVE-2007-3477 The imagearc() and imagefilledarc() routines in libgd allow an attacker in control of the parameters used to specify the degrees of arc for those drawing functions to perform a denial of service attack (excessive CPU consumption). CVE-2007-3996 Multiple integer overflows exist in libgd's image resizing and creation routines these weaknesses allow an attacker in control of the parameters passed to those routines to induce a crash or execute arbitrary code with the privileges of the user running an application or interpreter linked against libgd2. For the stable distribution (etch), these problems have been fixed in version 2.0.33-5.2etch1. For the unstable distribution (sid), the problem has been fixed in version 2.0.35.dfsg-1. We recommend that you upgrade your libgd2 packages.