Auth bypass in Clastix Capsule-Proxy

CVE-2023-48312

capsule-proxy is a reverse proxy for the capsule operator project. Affected versions are subject to a privilege escalation vulnerability which is based on a missing check if the user is authenticated based on the `TokenReview` result. All the clusters running with the `anonymous-auth` Kubernetes API Server setting disable (set to `false`) are affected since it would be possible to bypass the token review mechanism, interacting with the upper Kubernetes API Server. This privilege escalation cannot be exploited if you're relying only on client certificates (SSL/TLS). This vulnerability has been addressed in version 0.4.6. Users are advised to upgrade.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (45.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-48312: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-48312?
CVE-2023-48312 is a critical-severity vulnerability in Clastix Capsule-Proxy, classified under Improper Authentication. CVSS score: 9.8/10. Published 2023-11-24.
How severe is CVE-2023-48312?
Critical severity. CVSS v3 base score is 9.8 out of 10.