5.2.8 Minimize the admission of containers with added capabilities - allowedCapabilities

Information

Do not generally permit containers with capabilities assigned beyond the default set.

Rationale:

Containers run with a default set of capabilities as assigned by the Container Runtime. Capabilities outside this set can be added to containers which could expose them to risks of container breakout attacks.

There should be at least one Security Context Constraint (SCC) defined which prevents containers with capabilities beyond the default set from launching.

If you need to run containers with additional capabilities, this should be defined in a separate SCC and you should carefully check RBAC controls to ensure that only limited service accounts and users are given permission to access that SCC.

Impact:

Pods with containers which require capabilities outside the default set will not be permitted.

Solution

Utilize the restricted-v2 SCC or create an SCC that sets allowedCapabilities and defaultAddCapabilities to an empty list and take it into use by assigning it to applicable users and groups.

Default Value:

By default authenticated users are allowed to use the restricted-v2 SCC, which drops all container capabilities.

See Also

https://workbench.cisecurity.org/benchmarks/14166

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, 800-53|CM-7, CSCv7|5.2

Plugin: OpenShift

Control ID: b14da732ae2aa7e80aceaa5a10ab42608244275e0ec72c3e99ccd9ff228353e0