The Security - Keychain component in Apple OS X before 10.9.4 does not properly implement keystroke observers, which allows physically proximate attackers to bypass the screen-lock protection mechanism, and enter characters into an arbitrary window under the lock window, via keyboard input.
Category : Permissions, Privileges, and Access Controls Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.