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Apple Mac OS X UFS filesystem integer overflow vulnerability

Vulnerability Note VU#552136

Original Release Date: 2007-01-16 | Last Revised: 2007-03-13


There is an integer overflow in the ffs_mountfs() function, which is used by Apple's OS X operating system to handle UFS disc images.


Unix File System (UFS) is a file system used by Unix and other similar operating systems. Apple OS X supports UFS, partitions, and images.

There is an integer overflow error in the ffs_mountfs() function that may occur when an OS X system opens a UFS disc image. To trigger the overflow, an attacker would need to convince a user to open a specially crafted disc image. Note that the Safari web browser's default settings consider UFS disc images to be a safe file type, and will automatically open them after downloading.


A remote, unauthenticated attacker with the ability to supply a specially crafted DMG file may be able to cause an affected system to crash, thereby creating a denial of service. The original reporter states that an attacker may also be able to execute arbitrary code using this vulnerability. However, this has not been confirmed.


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

Disable "Open 'safe' files after downloading"

Disable the option "Open 'safe' files after downloading," as specified in the Securing Your Web Browser document. This will help prevent automatic exploitation of this and other vulnerabilities.

Vendor Information


Apple Computer, Inc. Affected

Updated:  March 13, 2007



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


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This issue was reported by LMH on the month of Apple bugs website.

This document was written by Ryan Giobbi.

Other Information

CVE IDs: CVE-2006-5679
Severity Metric: 1.14
Date Public: 2007-01-10
Date First Published: 2007-01-16
Date Last Updated: 2007-03-13 21:32 UTC
Document Revision: 21

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