Software Engineering Institute

Hierarchical File System (HFS+) is a file system that supports files that use 32-bit block addresses and Unicode file and folder naming conventions. UDTO is a format specification used to create DVD/CD-R master disk images. A vulnerability exists in the way Mac OS X handles corrupted UDTO HFS+ image structures. This vulnerability could lead to memory corruption.

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

A remote, unauthenticated attacker may be able to cause a denial-of-service condition.

Apply an upgrade
Apple has issued an upgrade to address this issue. See Apple Security Update 2007-003 for more details.

Disable the "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 DMG files from untrusted sources

Do not download DMG 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.