Prevent cr8escape (CVE-2022-0811)

 1apiVersion: kyverno.io/v1
 2kind: ClusterPolicy
 3metadata:
 4  name: prevent-cr8escape
 5  annotations:
 6    policies.kyverno.io/title: Prevent cr8escape (CVE-2022-0811)
 7    policies.kyverno.io/category: Other
 8    policies.kyverno.io/severity: high
 9    kyverno.io/kyverno-version: 1.6.0
10    policies.kyverno.io/minversion: 1.6.0
11    kyverno.io/kubernetes-version: "1.23"
12    policies.kyverno.io/subject: Pod
13    policies.kyverno.io/description: >-
14      A vulnerability "cr8escape" (CVE-2022-0811) in CRI-O the container runtime engine
15      underpinning Kubernetes allows attackers to escape from a Kubernetes container
16      and gain root access to the host. The recommended remediation is to disallow
17      sysctl settings with + or = in their value.      
18spec:
19  validationFailureAction: enforce
20  background: true
21  rules:
22    - name: restrict-sysctls-cr8escape
23      match:
24        any:
25        - resources:
26            kinds:
27              - Pod
28      validate:
29        message: "characters '+' or '=' are not allowed in sysctls values"      
30        pattern:
31          spec:
32            =(securityContext):
33              =(sysctls):
34                - =(value): "!*+* & !*=*"