Security Resilience

CVE-2023-27593

Cilium ≤ 1.11.15

Published
17 March 2023
Modified
21 November 2024
CVSS Score v3.1 4.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0022 11th percentile
Risk Priority 34 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-2023-27593 is a medium-severity Incorrect Default Permissions (CWE-276) vulnerability in Cilium Cilium. Its CVSS base score is 4.4 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Services File Permissions Weakness (T1574.010); ranked at the 11th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.11.15, 1.12.8, and 1.13.1, an attacker with access to a Cilium agent pod can write to `/opt/cni/bin` due to a `hostPath` mount of that directory…

more

in the agent pod. By replacing the CNI binary with their own malicious binary and waiting for the creation of a new pod on the node, the attacker can gain access to the underlying node. The issue has been fixed and the fix is available on versions 1.11.15, 1.12.8, and 1.13.1. Some workarounds are available. Kubernetes RBAC should be used to deny users and service accounts `exec` access to Cilium agent pods. In cases where a user requires `exec` access to Cilium agent pods, but should not have access to the underlying node, no workaround is possible.

CWE(s)
CWE-276

Related Threats

MITRE ATT&CK Enterprise Techniques

T1574.010 Services File Permissions Weakness Stealth
Adversaries may execute their own malicious payloads by hijacking the binaries used by services.
attack.mitre.org →
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
T1010 Application Window Discovery Discovery
Adversaries may attempt to get a listing of open application windows.
attack.mitre.org →
T1011.001 Exfiltration Over Bluetooth Exfiltration
Adversaries may attempt to exfiltrate data over Bluetooth rather than the command and control channel.
attack.mitre.org →
T1021.002 SMB/Windows Admin Shares Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-47825Same product: Cilium Cilium
CVE-2024-28860Same product: Cilium Cilium
CVE-2025-32793Same product: Cilium Cilium
CVE-2026-56742Same product: Cilium Cilium
CVE-2023-30851Same product: Cilium Cilium
CVE-2025-23028Same product: Cilium Cilium
CVE-2024-25631Same product: Cilium Cilium
CVE-2024-42487Same product: Cilium Cilium
CVE-2026-49445Same product: Cilium Cilium
CVE-2023-27595Same product: Cilium Cilium

Affected Assets

cilium
cilium
≤ 1.11.15 · 1.12.0 — 1.12.8 · 1.13.0 — 1.13.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

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

—

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.

AC-1 Policy and Procedures
addresses: CWE-276

Access control policy can specify and enforce secure default permissions for resources.

AC-6 Least Privilege
addresses: CWE-276

Guides setting of default permissions to the minimum required level.

CM-1 Policy and Procedures
addresses: CWE-276

Establishes requirements for appropriate default permissions on system resources as part of configuration management.

CM-2 Baseline Configuration
addresses: CWE-276

Baseline establishment and updates on install/upgrade ensure correct default permissions rather than insecure ones.

CM-6 Configuration Settings
addresses: CWE-276

Requiring the most restrictive settings instead of defaults prevents incorrect default permissions on resources.

CM-9 Configuration Management Plan
addresses: CWE-276

Requires documented processes that include setting and maintaining correct default permissions for configuration items.

PE-1 Policy and Procedures
addresses: CWE-276

Requires addressing secure default permissions in physical and environmental protection controls.

PL-11 Baseline Tailoring
addresses: CWE-276

Tailoring explicitly overrides or scopes default permission assignments in the baseline to match the system's actual risk and operational needs.

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.

ID.AM-08 partial match
blocks

Lifecycle management can encompass permission settings, yet the control is too broad to specifically mitigate incorrect defaults.

PR.AA-05 partial match
blocks

Defining and enforcing least-privilege access permissions directly prevents overly permissive defaults at install time.

PR.PS-01 partial match
blocks

Hardened baselines and configuration management explicitly require correct default file permissions.

PR.PS-06 partial match
blocks

Secure SDLC practices include establishing secure defaults, but address only the development-phase portion of the weakness.

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.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

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` (higher-evidence rows only; rows rated `none` are excluded).

Windows Server 2016 (2 rules)
  • V-224833 Permissions for program file directories must conform to minimum requirements. blocks CWE-276
  • V-224834 Permissions for the Windows installation directory must conform to minimum requirements. blocks CWE-276
Windows Server 2019 (2 rules)
  • V-205735 Windows Server 2019 permissions for program file directories must conform to minimum requirements. blocks CWE-276
  • V-205736 Windows Server 2019 permissions for the Windows installation directory must conform to minimum requirements. blocks CWE-276

References