Security Resilience

CVE-2023-2728

Kubernetes ≤ 1.24.14

Published
03 July 2023
Modified
13 February 2025
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.022 82th percentile
Risk Priority 56 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-2728 is a medium-severity Improper Input Validation (CWE-20) vulnerability in Kubernetes Kubernetes. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 18% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-2728 affects the ServiceAccount admission plugin in Kubernetes when the kubernetes.io/enforce-mountable-secrets annotation is enabled. The flaw allows users to launch ephemeral containers that bypass the mountable secrets policy, which normally restricts pods to referencing only secrets listed in the service account’s secrets field. Clusters are impacted solely when the admission plugin, the annotation, and ephemeral containers are used together.

An attacker with privileges to create pods and ephemeral containers can exploit the issue over the network to access secrets that would otherwise be blocked, resulting in disclosure and potential modification of sensitive data without affecting availability. The CVSS 6.5 score reflects the requirement for high privileges and the limited attack surface.

Advisories referenced in the Kubernetes security announcement and related lists describe the conditions under which clusters are exposed and point to updates that address the bypass in affected versions. The EPSS score has remained low, with a modest peak of 0.0602 that has since receded to 0.0485, indicating limited observed exploitation interest after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Users may be able to launch containers that bypass the mountable secrets policy enforced by the ServiceAccount admission plugin when using ephemeral containers. The policy ensures pods running with a service account may only reference secrets specified in the service…

more

account’s secrets field. Kubernetes clusters are only affected if the ServiceAccount admission plugin and the `kubernetes.io/enforce-mountable-secrets` annotation are used together with ephemeral containers.

CWE(s)

Related Threats

CVEs Like This One

CVE-2023-2727Same product: Kubernetes Kubernetes
CVE-2019-11248Same product: Kubernetes Kubernetes
CVE-2023-3955Same product: Kubernetes Kubernetes
CVE-2023-3676Same product: Kubernetes Kubernetes
CVE-2023-3893Same vendor: Kubernetes
CVE-2026-4342Same vendor: Kubernetes
CVE-2026-3288Same vendor: Kubernetes
CVE-2023-5528Same product: Kubernetes Kubernetes
CVE-2023-5044Same vendor: Kubernetes
CVE-2023-5043Same vendor: Kubernetes

Affected Assets

kubernetes
kubernetes
≤ 1.24.14 · 1.25.0 — 1.25.10 · 1.26.0 — 1.26.5

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

blocks

A.8.25 mandates security requirements, secure coding guidelines, checkpoints, testing (incl. code scans) and developer training in the SDLC, which reaches a slice of input validation defects but leaves the majority (incomplete enforcement, second-order inputs, parser differentials, post-validation canonicalization) unaddressed as in the SA-3 and A.8.28 anchors.

blocks

Mandating input controls that include integrity checks and input validation ensures that untrusted data is examined before use, blocking the root cause of many injection and malformed-data weaknesses.

blocks

Security-by-design principles explicitly call for data validation and sanitization at every layer, reducing the chance that malformed or malicious input will be processed without scrutiny.

prevents

Requiring language-specific secure coding standards, peer review, SAST and documented mitigation of common programming errors forces validation of all inputs before they are trusted.

finds

Testing against a defined set of requirements and using code review plus vulnerability scanning forces validation of inputs and handling of unanticipated conditions, reducing the chance that malformed data will be accepted.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-20, a class-level weakness, and none of its children carries one either.

References