CVE-2023-27595 Cilium eBPF filters may be temporarily removed during agent restart
Attackers can bypass network policies or disrupt connections during Cilium agent restarts due to temporary eBPF program detachment.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-27595?
CVE-2023-27595 is a medium-severity vulnerability in cilium, published on 17 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. In version 1.13.0, when Cilium is started, there is a short period when Cilium eBPF programs are not attached to the host. During this period, the host does not implement any of Cilium's featureset. This can cause disruption to newly established connections during this period due to the lack of Load Balancing, or can cause Network Policy bypass due to the lack of Network Policy enforcement during the window. This vulnerability impacts any Cilium-managed endpoints on the node (such as Kubernetes Pods), as well as the host network namespace (including Host Firewall). This vulnerability is fixed in Cilium 1.13.1 or later. Cilium releases 1.12.x, 1.11.x, and earlier are not affected. There are no known workarounds.
Weakness: CWE-755
Which versions are affected by CVE-2023-27595?
10 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 | From 1.13.0 | 1.13.1 |
github.com/cilium/cilium Go | From 1.13.0 | 1.13.1 |
github.com/cilium/cilium Go | From 1.13.0 | 1.13.1 |
cilium Bitnami | From 1.13.0 | 1.13.1 |
cilium-operator Bitnami | From 1.13.0 | 1.13.1 |
cilium-proxy Bitnami | From 1.13.0 to 1.13.0 | None |
4 more packages
hubble Bitnami | From 1.13.0 to 1.13.0 | None |
hubble-relay Bitnami | From 1.13.0 | 1.13.1 |
hubble-ui Bitnami | From 1.13.0 to 1.13.0 | None |
hubble-ui-backend Bitnami | From 1.13.0 to 1.13.0 | None |
Products include Cilium Cilium.
How do I fix CVE-2023-27595?
Upgrade github.com/cilium/cilium to 1.13.1 or later.
Is CVE-2023-27595 being exploited?
There is no known exploitation of CVE-2023-27595 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-2023-27595, BIT-cilium-operator-2023-27595, BIT-cilium-proxy-2023-27595, BIT-hubble-2023-27595, BIT-hubble-relay-2023-27595, BIT-hubble-ui-2023-27595 and 3 more.