Software Engineering Institute

Apple Mac OS X uses the Mach-O file format's ability to support more than one type of machine code to create Mac OS X Universal binaries. Apple Mac OS X contains a vulnerability in the way corrupted Universal Mach-O Binaries are handled. According to Apple Security Update 2007-003:

An integer overflow vulnerability exists in the loading of Universal Mach-O binaries. This could allow a malicious local user to cause a kernel panic or to obtain system privileges. This has been described on the Month of Kernel Bugs web site (MOKB-26-11-2006). This update addresses the issue by performing additional validation of Universal binaries.

We are aware of publicly available proof-of-concept code that demonstrates this vulnerability.

A remote, unauthenticated attacker may be able to execute arbitrary code with kernel privileges or cause a denial of service.

Upgrade

Apple has published Mac OS X 10.4.9 for Mac OS X 10.4 (Tiger) systems and Security Update 2007-003 for Mac OS X 10.3 (Panther) systems in response to this issue. See Apple Security Update 2007-003 for more details.

Disable Open “safe” files after downloading option

For instructions on how to disable the Open “safe” files after downloading option in Safari, please refer to the Safari section of the Securing Your Web Browser document.

Do not access Universal Binary files from untrusted sources

Do not download Universal Binary files from unknown or untrusted sources. Do not open unfamiliar or unexpected links, particularly those delivered in email messages. Please see Cyber Security Tip ST04-014.