Policy bypass via omitted ephemeral container images
Published Jul 3, 2023 · Updated Feb 13, 2025
Improper input validation in Kubernetes kube-apiserver allows remote authenticated users to launch policy-blocked container images. The ImagePolicyWebhook admission path omits images added through Pod.spec.ephemeralContainers from its ImageReview, so the policy backend does not evaluate them. Exploitation requires high privileges to update the ephemeralcontainers subresource, an enabled ImagePolicyWebhook, and pods using ephemeral containers.
Summary
What happened
Improper input validation in Kubernetes kube-apiserver allows remote authenticated users to launch policy-blocked container images. The ImagePolicyWebhook admission path omits images added through Pod.spec.ephemeralContainers from its ImageReview, so the policy backend does not evaluate them. Exploitation requires high privileges to update the ephemeralcontainers subresource, an enabled ImagePolicyWebhook, and pods using ephemeral containers.
The record
- CVE
- CVE-2023-2727
- Published
- Jul 3, 2023
- Updated
- Feb 13, 2025
- Vendor
- Kubernetes
- Product
- Kubernetes
- Classifications
- CWE-20, T1610
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 3, 2023CVE publishedPublication date reported by the CVE source.
- Feb 13, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=v1.24.14 <=<=
- Affected versionversion=v1.25.0 - v1.25.10
- Affected versionversion=v1.26.0 - v1.26.5
- Affected versionversion=v1.27.0 - v1.27.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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