Cilium up to 1.14.17/1.15.11/1.16.4 header information disclosure

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Cilium up to 1.14.17/1.15.11/1.16.4. The impacted element is an unknown function. Performing a manipulation of the argument header results in information disclosure. This vulnerability is identified as CVE-2025-23047. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Cilium up to 1.14.17/1.15.11/1.16.4. It has been classified as problematic. This affects an unknown functionality. The manipulation of the argument header with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. The summary by CVE is:

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. An insecure default `Access-Control-Allow-Origin` header value could lead to sensitive data exposure for users of Cilium versions 1.14.0 through 1.14.7, 1.15.0 through 1.15.11, and 1.16.0 through 1.16.4 who deploy Hubble UI using either Cilium CLI or via the Cilium Helm chart. A user with access to a Hubble UI instance affected by this issue could leak configuration details about the Kubernetes cluster which Hubble UI is monitoring, including node names, IP addresses, and other metadata about workloads and the cluster networking configuration. In order for this vulnerability to be exploited, a victim would have to first visit a malicious page. This issue is fixed in Cilium v1.14.18, v1.15.12, and v1.16.5. As a workaround, users who deploy Hubble UI using the Cilium Helm chart directly can remove the CORS headers from the Helm template as shown in the patch from commit a3489f190ba6e87b5336ee685fb6c80b1270d06d.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2025-23047 since 01/10/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 214906 (SUSE SLES15 / openSUSE 15 Security Update : govulncheck-vulndb (SUSE-SU-2025:0297-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.14.18, 1.15.12 or 1.16.5 eliminates this vulnerability. Applying the patch a3489f190ba6e87b5336ee685fb6c80b1270d06d is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (214906). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• Cilium

Version

• 1.14.0
• 1.14.1
• 1.14.2
• 1.14.3
• 1.14.4
• 1.14.5
• 1.14.6
• 1.14.7
• 1.14.8
• 1.14.9
• 1.14.10
• 1.14.11
• 1.14.12
• 1.14.13
• 1.14.14
• 1.14.15
• 1.14.16
• 1.14.17
• 1.15.0
• 1.15.1
• 1.15.2
• 1.15.3
• 1.15.4
• 1.15.5
• 1.15.6
• 1.15.7
• 1.15.8
• 1.15.9
• 1.15.10
• 1.15.11
• 1.16.0
• 1.16.1
• 1.16.2
• 1.16.3
• 1.16.4

License

• open-source

Website

• Product: https://github.com/cilium/cilium/

CPE 2.3info

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CPE 2.2info

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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