Race condition in Apple iOS 4.0 through 4.1 for iPhone 3G and later allows physically proximate attackers to bypass the passcode lock by making a call from the Emergency Call screen, then quickly pressing the Sleep/Wake button.
Concurrent Execution using Shared Resource with Improper Synchronization The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.