The software was unveiled on 5 September to support a new range of iPods and a ring-tone builder.
The vulnerability lies in the cover art display system used by iTunes. Cover art is displayed while a track is playing, but is also used to navigate music in the Cover Flow interface.
By creating a specially malformed file, an attacker could cause an application crash or execute arbitrary code.
Remote code execution flaws are considered to be the most serious type of vulnerability, because they can be used by attackers to install malware.
Apple credited David Thiel, a security researcher at iSec Partners, with discovering the vulnerability.
Security firm Secunia rated the flaw as 'highly critical', the second highest of its alert levels. Secunia and the US Computer Emergency Readiness Team recommended that users install the update as soon as possible.
ITunes has yet to fall victim to a major attack, but other Apple products have been targeted by malware authors.
Late last year a piece of malware spread through MySpace preying on users via a flaw in Apple's QuickTime software.
The infamous MPack exploit tool has also been known to target Quicktime vulnerabilities.
Apple slips security fix into iTunes update
By Shaun Nichols on Sep 10, 2007 3:20PM