pngrtran.c in libpng before 1.0.29 and 1.2.x before 1.2.21 use (1) logical instead of bitwise operations and (2) incorrect comparisons, which might allow remote attackers to cause a denial of service (crash) via a crafted PNG image.
http://www.vupen.com/english/advisories/2009/1560
http://www.vupen.com/english/advisories/2009/1462
http://www.vupen.com/english/advisories/2008/1697
http://www.vupen.com/english/advisories/2008/0924/references
http://www.vupen.com/english/advisories/2007/3390
http://www.us-cert.gov/cas/techalerts/TA08-150A.html
http://www.ubuntu.com/usn/usn-538-1
http://www.securityfocus.com/bid/25956
http://www.securityfocus.com/archive/1/489135/100/0/threaded
http://www.securityfocus.com/archive/1/483582/100/0/threaded
http://www.mandriva.com/security/advisories?name=MDKSA-2007:217
http://www.gentoo.org/security/en/glsa/glsa-200805-07.xml
http://www.gentoo.org/security/en/glsa/glsa-200711-08.xml
http://www.coresecurity.com/?action=item&id=2148
http://support.avaya.com/elmodocs2/security/ASA-2009-208.htm
http://slackware.com/security/viewer.php?l=slackware-security&y=2007&m=slackware-security.520323
http://secunia.com/advisories/35386
http://secunia.com/advisories/35302
http://secunia.com/advisories/30430
http://secunia.com/advisories/30161
http://secunia.com/advisories/29420
http://secunia.com/advisories/27746
http://secunia.com/advisories/27629
http://secunia.com/advisories/27529
http://secunia.com/advisories/27405
http://secunia.com/advisories/27284
http://secunia.com/advisories/27093
http://lists.apple.com/archives/security-announce/2008/Mar/msg00001.html
http://lists.apple.com/archives/security-announce/2008//May/msg00001.html
http://docs.info.apple.com/article.html?artnum=307562
http://bugs.gentoo.org/show_bug.cgi?id=195261
http://android-developers.blogspot.com/2008/03/android-sdk-update-m5-rc15-released.html