The remote host is missing an update to libpng announced via advisory DSA 2072-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202072-1

Several vulnerabilities have been discovered in libpng, a library for reading and writing PNG files. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2010-1205 It was discovered a buffer overflow in libpng which allows remote attackers to execute arbitrary code via a PNG image that triggers an additional data row. CVE-2010-2249 It was discovered a memory leak in libpng which allows remote attackers to cause a denial of service (memory consumption and application crash) via a PNG image containing malformed Physical Scale (aka sCAL) chunks For the stable distribution (lenny), these problems have been fixed in version 1.2.27-2+lenny4. For the testing (squeeze) and unstable (sid) distribution, these problems have been fixed in version 1.2.44-1 We recommend that you upgrade your libpng package.