This is a potential security issue, you are being redirected to https://csrc.nist.gov.
An unintended or unauthorized intra-system channel that enables two cooperating entities to transfer information in a way that violates the system's security policy but does not exceed the entities' access authorizations.
CNSSI 4009-2015 from IETF RFC 4949 Ver 2
NIST SP 800-53 Rev. 5 from CNSSI 4009-2015