Public Vulnerability Reports

Apple Mac OS X CoreGraphics PDF Type1 Font Integer Overflow Vulnerability

31.07.08

BACKGROUND

Mac OS X is a Unix operating system built from the XNU kernel. Mac OS X provides all the standard Unix capabilities and tools with an additional GUI component. For more information, see the vendor's site found at the following link URL.

http://www.apple.com/macosx/

DESCRIPTION

Remote exploitation of an integer overflow vulnerability in Apple Inc.'s Mac OS X could allow an attacker to execute arbitrary code with the privileges of the currently logged in user.

This vulnerability exists due to the way PDF files containing Type 1 fonts are handled. When processing a font with an overly large length, integer overflow could occur. This issue leads to heap corruption which can allow for arbitrary code execution.

ANALYSIS

Exploitation of this issue allows an attacker to execute arbitrary code. An attacker could exploit this issue via multiple attack vectors. The most appealing vector for attack is Safari. An attacker could host a malformed PDF file on a website and entice a targeted user to open a URL. Upon opening the URL in Safari the PDF file will be automatically parsed and exploitation will occur. While this is the most appealing attack vector, the file can also be attached to an e-mail. Any application which uses the Apple libraries for file open dialogs will crash upon previewing the malformed PDF document.

DETECTION

iDefense has confirmed the existence of this vulnerability in Mac OS X version 10.5.2. Previous versions may also be affected.

WORKAROUND

iDefense is currently unaware of any workarounds for this issue.

VENDOR RESPONSE

Apple addressed this vulnerability within their Mac OS X 2008-005 security update. More information is available at the following URL.

http://support.apple.com/kb/HT2647

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2008-2322 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems.

DISCLOSURE TIMELINE

07/09/2008 Initial vendor notification
07/10/2008 Initial vendor response
07/31/2008 Coordinated public disclosure

CREDIT

This vulnerability was reported to iDefense by Pariente Kobi.

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LEGAL NOTICES

Copyright © 2008 Verisign, Inc.

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