SecurityAgent in Apple OS X before 10.11.1 does not prevent synthetic clicks from reaching keychain windows, which allows attackers to bypass intended access restrictions via a crafted app.
https://support.apple.com/HT205375
https://euvd.enisa.europa.eu/vulnerability/EUVD-2015-5889
http://lists.apple.com/archives/security-announce/2015/Oct/msg00005.html