CVE-2023-27593 cilium-agent container can access the host via `hostPath` mount
An attacker with pod access can replace CNI binaries via hostPath mount to execute code on the underlying node.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-27593?
CVE-2023-27593 is a medium-severity vulnerability in cilium, published on 17 Mar 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-276
Which versions are affected by CVE-2023-27593?
13 open source packages ship an affected version, including github.com/cilium/cilium, cilium and cilium-operator. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/cilium/cilium Go | All versions | 1.11.15 |
github.com/cilium/cilium Go | All versions | 1.11.15 |
github.com/cilium/cilium Go | From 1.12.0 | 1.12.8 |
github.com/cilium/cilium Go | From 1.12.0 | 1.12.8 |
github.com/cilium/cilium Go | From 1.13.0 | 1.13.1 |
github.com/cilium/cilium Go | From 1.13.0 | 1.13.1 |
7 more packages
cilium Bitnami | All versions | 1.11.15, 1.12.8, 1.13.1 |
cilium-operator Bitnami | All versions | 1.11.15, 1.12.8, 1.13.1 |
cilium-proxy Bitnami | All versions | 1.11.15, 1.12.8, 1.13.1 |
hubble Bitnami | All versions | 1.11.15, 1.12.8, 1.13.1 |
hubble-relay Bitnami | All versions | 1.11.15, 1.12.8, 1.13.1 |
hubble-ui Bitnami | All versions | 1.11.15, 1.12.8, 1.13.1 |
hubble-ui-backend Bitnami | All versions | 1.11.15, 1.12.8, 1.13.1 |
Products include Cilium Cilium.
How do I fix CVE-2023-27593?
Upgrade github.com/cilium/cilium to a fixed version for your release line: 1.11.15, 1.12.8 or 1.13.1.
Is CVE-2023-27593 being exploited?
There is no known exploitation of CVE-2023-27593 in the wild and no public exploit code.
Other vulnerabilities in cilium
- CVE-2026-49445 Cilium: Sensitive information disclosure and cluster disruption via local Envoy admin socket access
- CVE-2022-29178 Incorrect Default Permissions in Cilium
- CVE-2024-28860 Insecure IPsec transport encryption in Cilium
- CVE-2026-41520 Cillium exposes sensitive information included in the cilium-bugtool debug archive
- CVE-2024-37307 Cilium leaks sensitive information in cilium-bugtool
Sources
Also known as 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 and 2 more.