CoreGraphics in Apple Mac OS X 10.4.6, when "Enable access for assistive devices" is on, allows an application to bypass restrictions for secure event input and read certain events from other applications in the same window session by using Quartz Event Services.
https://exchange.xforce.ibmcloud.com/vulnerabilities/26409
http://www.vupen.com/english/advisories/2006/1779
http://www.us-cert.gov/cas/techalerts/TA06-132A.html
http://www.securityfocus.com/bid/17951
http://securitytracker.com/id?1016079
http://secunia.com/advisories/20077
http://lists.apple.com/archives/security-announce/2006/May/msg00003.html