The remote Debian host is missing a security-related update.
Several vulnerabilities have been discovered in the libpng PNG library. The Common Vulnerabilities and Exposures project identifies the following problems : - CVE-2015-7981 Qixue Xiao discovered an out-of-bounds read vulnerability in the png_convert_to_rfc1123 function. A remote attacker can potentially take advantage of this flaw to cause disclosure of information from process memory. - CVE-2015-8126 Multiple buffer overflows were discovered in the png_set_PLTE and png_get_PLTE functions. A remote attacker can take advantage of this flaw to cause a denial of service (application crash) via a small bit-depth value in an IHDR (image header) chunk in a PNG image.
Upgrade the libpng packages. For the oldstable distribution (wheezy), these problems have been fixed in version 1.2.49-1+deb7u1. For the stable distribution (jessie), these problems have been fixed in version 1.2.50-2+deb8u1.