Multiple security vulnerabilities have been discovered in the Portable Network Graphics (PNG) Library libpng(3) which also affect Netscape 7 shipped with Solaris since Netscape 7 includes the affected libpng routines. This may allow an unprivileged user to execute arbitrary code with the privileges of a local user. This condition can be exploited when the local user has loaded a Portable Network Graphics (PNG) format image file supplied by an untrusted user and views a malicious web site or views an e-mail message containing a malformed PNG image with that application.
News source: Sun.com