EEYEB-20051117B Apple iTunes (QuickTime.qts) Heap Overflow

Release Date:
January 10, 2006

Date Reported:
November 17, 2005

Patch Development Time (In Days):
54 Days

Severity:
High (Code Execution)

Vendor:
Apple

Systems Affected:
Quicktime on Windows 2000
Quicktime on Windows XP
Quicktime on Mac OS X 10.3.9

Apple iTunes on Windows 2000
Apple iTunes on Windows XP
Apple iTunes on OS X 10.3.9

Overview:
eEye Digital Security has discovered a critical vulnerability in Apple
iTunes. The vulnerability allows an attacker to reliably overwrite heap
memory with user-controlled data and execute arbitrary code in the
context of the user who executed iTunes.

This specific flaw exists within the QuickTime.qts file which many
applications access QuickTime's functionality through. By specially
crafting atoms within a movie file, a direct heap overwrite is
triggered, and reliable code execution is then possible.

Technical Details:
The code in QuickTime.qts responsible for copying Movie Resource atom
type sizes in a QuickTime-format movie into an array allocated on the
heap. According to developer.apple.com, the format of the Movie Resource
atom is as follows:

Field           Description
---------------------------
Atom Size       4 bytes
Atom Type       4 bytes
Data            Variable

By supplying the .MOV file with a large atom size results in a
insufficiently-sized heap block to be allocated, resulting in a complete
heap memory overwrite ultimately failing in the List_Component()
function.  

References
QuickTime: QuickTime File Format
http://developer.apple.com/documentation/QuickTime/QTFF/index.html

Vendor Status:
Apple has released a patch for this vulnerability. The patch is
available via the Updates section of the affected applications.
This vulnerability has been assigned the CVE identifier CVE-2005-4092.

Credit:
Discovery: Karl Lynn

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