Updated libpng packages that fix several issues are now available.
The libpng package contains a library of functions for creating and manipulating PNG (Portable Network Graphics) image format files. During a source code audit, Chris Evans discovered several buffer overflows in libpng. An attacker could create a carefully crafted PNG file in such a way that it would cause an application linked with libpng to execute arbitrary code when the file was opened by a victim. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0597 to these issues. In addition, this audit discovered a potential NULL pointer dereference in libpng (CAN-2004-0598) and several integer overflow issues (CAN-2004-0599). An attacker could create a carefully crafted PNG file in such a way that it would cause an application linked with libpng to crash when the file was opened by the victim. Red Hat would like to thank Chris Evans for discovering these issues. For users of Red Hat Enterprise Linux 2.1 these patches also include a more complete fix for the out of bounds memory access flaw (CAN-2002-1363). All users are advised to update to the updated libpng packages which contain backported security patches and are not vulnerable to these issues.