AC-11: Device Lock
Control Family:
Threats Addressed:
Baselines:
Previous Version:
- NIST Special Publication 800-53 Revision 4:
- AC-11: Session Lock
Control Statement
- Prevent further access to the system by [Assignment (one or more): initiating a device lock after [Assignment: organization-defined time period] of inactivity, requiring the user to initiate a device lock before leaving the system unattended] ; and
- Retain the device lock until the user reestablishes access using established identification and authentication procedures.
Supplemental Guidance
Device locks are temporary actions taken to prevent logical access to organizational systems when users stop work and move away from the immediate vicinity of those systems but do not want to log out because of the temporary nature of their absences. Device locks can be implemented at the operating system level or at the application level. A proximity lock may be used to initiate the device lock (e.g., via a Bluetooth-enabled device or dongle). User-initiated device locking is behavior or policy-based and, as such, requires users to take physical action to initiate the device lock. Device locks are not an acceptable substitute for logging out of systems, such as when organizations require users to log out at the end of workdays.
OT Discussion
This control assumes a staffed environment where users interact with system displays. This control may be tailored appropriately where systems do not have displays configured, systems are placed in an access-controlled facility or locked enclosure, or immediate operator response is required in emergency situations. Example compensating controls include locating the display in an area with physical access controls that limit access to individuals with permission and need-to-know for the displayed information.
Control Enhancements
AC-11(1): Pattern-hiding Displays
Baseline(s):
- Moderate
- High
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Conceal, via the device lock, information previously visible on the display with a publicly viewable image.