CVE-2023-27595

Cilium eBPF filters may be temporarily removed during agent restart

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.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.04%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com
Affected: cilium cilium
Published at:
Updated at:

References

Link Tags
https://github.com/cilium/cilium/security/advisories/GHSA-r5x6-w42p-jhpp third party advisory
https://github.com/cilium/cilium/pull/24336 third party advisory
https://github.com/cilium/cilium/releases/tag/v1.13.1 third party advisory

Frequently Asked Questions

What is the severity of CVE-2023-27595?
CVE-2023-27595 has been scored as a medium severity vulnerability.
How to fix CVE-2023-27595?
To fix CVE-2023-27595, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-27595 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-27595 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-27595?
CVE-2023-27595 affects cilium cilium.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.