The png_handle_sCAL function in pngrutil.c in libpng 1.0.x before 1.0.55, 1.2.x before 1.2.45, 1.4.x before 1.4.8, and 1.5.x before 1.5.4 does not properly handle invalid sCAL chunks, which allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly have unspecified other impact via a crafted PNG image that triggers the reading of uninitialized memory.
https://exchange.xforce.ibmcloud.com/vulnerabilities/68536
https://bugzilla.redhat.com/show_bug.cgi?id=720612
http://www.ubuntu.com/usn/USN-1175-1
http://www.securityfocus.com/bid/48618
http://www.openwall.com/lists/oss-security/2011/07/13/2
http://www.libpng.org/pub/png/libpng.html
http://www.kb.cert.org/vuls/id/819894
http://www.debian.org/security/2011/dsa-2287
http://support.apple.com/kb/HT5281
http://support.apple.com/kb/HT5002
http://security.gentoo.org/glsa/glsa-201206-15.xml
http://lists.fedoraproject.org/pipermail/package-announce/2011-July/063118.html
http://lists.apple.com/archives/security-announce/2012/May/msg00001.html
http://lists.apple.com/archives/Security-announce/2011//Oct/msg00003.html