  We present new results on the application of semantic- and knowledge-based
reasoning techniques to the analysis of cloud deployments. In particular, to
the security of Infrastructure as Code configuration files, encoded as
description logic knowledge bases. We introduce an action language to model
mutating actions; that is, actions that change the structural configuration of
a given deployment by adding, modifying, or deleting resources. We mainly focus
on two problems: the problem of determining whether the execution of an action,
no matter the parameters passed to it, will not cause the violation of some
security requirement (static verification), and the problem of finding
sequences of actions that would lead the deployment to a state where
(un)desirable properties are (not) satisfied (plan existence and plan
synthesis). For all these problems, we provide definitions, complexity results,
and decision procedures.
