T1461 Lockscreen Bypass

An adversary with physical access to a mobile device may seek to bypass the device’s lockscreen. Several methods exist to accomplish this, including:

Biometric spoofing: If biometric authentication is used, an adversary could attempt to spoof a mobile device’s biometric authentication mechanism. Both iOS and Android partly mitigate this attack by requiring the device’s passcode rather than biometrics to unlock the device after every device restart, and after a set or random amount of time.⁴³
Unlock code bypass: An adversaries could attempt to brute-force or otherwise guess the lockscreen passcode (typically a PIN or password), including physically observing (“shoulder surfing”) the device owner’s use of the lockscreen passcode. Mobile OS vendors partly mitigate this by implementing incremental backoff timers after a set number of failed unlock attempts, as well as a configurable full device wipe after several failed unlock attempts.
Vulnerability exploit: Techniques have been periodically demonstrated that exploit mobile devices to bypass the lockscreen. The vulnerabilities are generally patched by the device or OS vendor once disclosed.¹²

Mitigations

ID	Mitigation	Description
M1012	Enterprise Policy	Enterprises can provision policies to mobile devices that require a minimum complexity (length, character requirements, etc.) for the device passcode, and cause the device to wipe all data if an incorrect passcode is entered too many times. Both policies would mitigate brute-force, guessing, or shoulder surfing of the device passcode. Enterprises can also provision policies to disable biometric authentication, however, biometric authentication can help make using a longer, more complex passcode more practical because it does not need to be entered as frequently.
M1001	Security Updates	OS security updates typically contain exploit patches when disclosed.