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-2015-8472 It was discovered that the original fix for CVE-2015-8126 was incomplete and did not detect a potential overrun by applications using png_set_PLTE directly. A remote attacker can take advantage of this flaw to cause a denial of service (application crash). - CVE-2015-8540 Xiao Qixue and Chen Yu discovered a flaw in the png_check_keyword function. A remote attacker can potentially take advantage of this flaw to cause a denial of service (application crash).
Upgrade the libpng packages. For the oldstable distribution (wheezy), these problems have been fixed in version 1.2.49-1+deb7u2. For the stable distribution (jessie), these problems have been fixed in version 1.2.50-2+deb8u2.