CVE-2023-34091

Kyverno resource with a deletionTimestamp may allow policy circumvention

Description

Kyverno is a policy engine designed for Kubernetes. In versions of Kyverno prior to 1.10.0, resources which have the `deletionTimestamp` field defined can bypass validate, generate, or mutate-existing policies, even in cases where the `validationFailureAction` field is set to `Enforce`. This situation occurs as resources pending deletion were being consciously exempted by Kyverno, as a way to reduce processing load as policies are typically not applied to objects which are being deleted. However, this could potentially result in allowing a malicious user to leverage the Kubernetes finalizers feature by setting a finalizer which causes the Kubernetes API server to set the `deletionTimestamp` and then not completing the delete operation as a way to explicitly to bypass a Kyverno policy. Note that this is not applicable to Kubernetes Pods but, as an example, a Kubernetes Service resource can be manipulated using an indefinite finalizer to bypass policies. This is resolved in Kyverno 1.10.0. There is no known workaround.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.03%
Vendor Advisory github.com
Affected: kyverno kyverno
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2023-34091?
CVE-2023-34091 has been scored as a medium severity vulnerability.
How to fix CVE-2023-34091?
To fix CVE-2023-34091, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-34091 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-34091 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-34091?
CVE-2023-34091 affects kyverno kyverno.
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