Integer overflow in QuickLook, as used in Apple Mac OS X before 10.6.7 and MobileSafari in Apple iOS before 4.2.7 and 4.3.x before 4.3.2, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a Microsoft Office document with a crafted size field in the OfficeArtMetafileHeader, related to OfficeArtBlip, as demonstrated on the iPhone by Charlie Miller and Dion Blazakis during a Pwn2Own competition at CanSecWest 2011.
http://www.zerodayinitiative.com/advisories/ZDI-11-109/
http://www.zdnet.com/blog/security/charlie-miller-wins-pwn2own-again-with-iphone-4-exploit/8378
http://support.apple.com/kb/HT5003
http://support.apple.com/kb/HT4607
http://support.apple.com/kb/HT4581
http://secunia.com/advisories/44154
http://lists.apple.com/archives/security-announce/2011/Mar/msg00006.html
http://lists.apple.com/archives/security-announce/2011//Apr/msg00001.html
http://lists.apple.com/archives/security-announce/2011//Apr/msg00000.html
http://lists.apple.com/archives/Security-announce/2011//Oct/msg00005.html