What is CVE-2021-31921?

CVE-2021-31921 is a critical-severity vulnerability in Istio, classified under Missing Authorization. CVSS score: 9.8/10. Published 2021-06-02.

How severe is CVE-2021-31921?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Istio

CVE-2021-31921

Istio before 1.8.6 and 1.9.x before 1.9.5 contains a remotely exploitable vulnerability where an external client can access unexpected services in the cluster, bypassing authorization checks, when a gateway is configured with AUTO_PASSTHROUGH routing configuration.

Vulnerability class: Broken Access Control

EPSS: 0.015 (70.8th percentile) — read the EPSS interpretation.

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.

Affected products

Istio
N/a — versions n/a

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

cve@mitre.org (Exploit, x_refsource_MISC, Vendor Advisory)

Frequently asked questions

What is CVE-2021-31921?: CVE-2021-31921 is a critical-severity vulnerability in Istio, classified under Missing Authorization. CVSS score: 9.8/10. Published 2021-06-02.
How severe is CVE-2021-31921?: Critical severity. CVSS v3 base score is 9.8 out of 10.