Is CVE-2021-31921 actively exploited?

CVE-2021-31921 has no public evidence of in-the-wild exploitation as of 2024-11-21.

What is the CVSS score for CVE-2021-31921?

CVE-2021-31921 has a CVSS score of 9.8 (CRITICAL severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

How do I patch CVE-2021-31921?

Patch guidance is available from istio security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2021-31921.

Which products are affected by CVE-2021-31921?

2 products: istio istio, istio istio.

Fix CVE-2021-31921 - CRITICAL istio istio

Description

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.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-862 · Missing Authorization

Metadata

Primary Vendor: ISTIO
Published: 6/2/2021
Last Modified: 11/21/2024
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

istio : istioistio : istio

Remediation Guidance

Executive Summary

Cite this page

CVE-2021-31921. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2021-31921

View on NIST NVD

CVE-2021-31921 vulnerability