Cyber Resilience

CVE-2024-21403

Microsoft Azure Kubernetes Service

Published
13 February 2024
Modified
10 August 2026
Patch / advisory
CVSS Score v3.1 9.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.013 69th percentile
Risk Priority 66 floored blend · peak EPSS

Summary

CVE-2024-21403 is a critical-severity Files or Directories Accessible to External Parties (CWE-552) vulnerability in Microsoft Azure Kubernetes Service. Its CVSS base score is 9.0 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked in the top 31% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Microsoft Azure Kubernetes Service Confidential Container Elevation of Privilege Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
T1039 Data from Network Shared Drive Collection
Adversaries may search network shares on computers they have compromised to find files of interest.
T1119 Automated Collection Collection
Once established within a system or network, an adversary may use automated techniques for collecting internal data.
T1530 Data from Cloud Storage Collection
Adversaries may access data from cloud storage.
T1552.001 Credentials In Files Credential Access
Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials.
T1552.004 Private Keys Credential Access
Adversaries may search for private key certificate files on compromised systems for insecurely stored credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-32185Same vendor: Microsoft
CVE-2023-29332Same product: Microsoft Azure Kubernetes Service
CVE-2024-21376Same product: Microsoft Azure Kubernetes Service
CVE-2026-57990Same vendor: Microsoft
CVE-2025-21264Same vendor: Microsoft
CVE-2026-35440Same vendor: Microsoft
CVE-2025-66389Same vendor: Microsoft
CVE-2023-31017Same vendor: Microsoft
CVE-2024-3037Same vendor: Microsoft
CVE-2024-43554Same vendor: Microsoft

Affected Assets

microsoft
azure kubernetes service
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V8.4.2

Mitigating Controls (NIST 800-53 r5) AI

AC-3 directly enforces authorization checks on access to files and directories, stopping unauthorized external exposure.

AC-6 limits granted privileges, reducing the chance that files or directories become reachable by external parties.

AC-4 enforces information flow rules that can block unauthorized external access to files or directories.

Mitigating Controls (NIST CSF 2.0) AI

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

PR.AA-05 mostly match
prevents

Enforcing least-privilege permissions and authorization policies directly prevents unauthorized file/directory exposure.

PR.IR-01 mostly match
prevents

Logical segmentation and access protections stop external parties from reaching files that should remain internal.

PR.DS-01 partial match
prevents

Data-at-rest protections such as encryption or ACLs reduce the impact of unintended file exposure.

PR.PS-01 partial match
prevents

Hardened configuration baselines commonly include file-system permission settings that limit external access.

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.

mitigates

By tracing and retrieving all copies of information stored on endpoint and portable devices, the control reduces the likelihood that files remain accessible outside the organization’s security perimeter.

mitigates

Labeling information according to its sensitivity and specifying corresponding protection measures makes it less probable that files or directories containing sensitive content will be left accessible to external parties.

mitigates

Including asset location and ownership in the inventory, combined with secure disposal procedures, decreases the chance that files or directories remain accessible to external parties after they should have been removed or restricted.

mitigates

Solid perimeters and locked external access points stop files, devices, or directories containing sensitive data from being reachable by external parties who could otherwise walk in or break in.

mitigates

Authorizing and logging the removal of storage media, disabling unused ports, and monitoring transfers limit the exposure of files or directories to external parties outside the organization’s controlled environment.

mitigates

Segregating delivery/loading zones and controlling external doors prevents external parties from reaching directories or resources that should remain inaccessible.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248579 OL 8 must restrict access to the kernel message buffer. prevents CWE-552
  • V-248597 There must be no "shosts.equiv" files on the OL 8 operating system. prevents CWE-552

References