PT-2021-19596 · Istio · Istio

John Howard · Published 2021-06-02 · Updated 2022-05-01 · CVE-2021-31921

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions: Istio versions 1.8.0 through 1.8.6 Istio versions 1.9.0 through 1.9.5

Description: The issue allows an external client to access unexpected services in the cluster, bypassing authorization checks, when a gateway is configured with AUTO PASSTHROUGH routing configuration. This can be exploited remotely.

Recommendations: For Istio versions 1.8.0 through 1.8.6, update to version 1.8.6 or later. For Istio versions 1.9.0 through 1.9.5, update to version 1.9.5 or later. As a temporary workaround, consider changing the gateway routing configuration from AUTO PASSTHROUGH to a more restrictive setting to minimize the risk of exploitation.

Exploit

Fix

Missing Authorization

Weakness Enumeration

CWE-862

Related Identifiers

CVE-2021-31921

RHSA-2021:2061

RHSA-2021:2085

Affected Products

Istio

References · 8

• 🔥 https://istio.io/latest/news/security/istio-security-2021-006 · Exploit
• https://linux.oracle.com/errata/ELSA-2021-9397.html · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2021-9399.html · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-31921 · Security Note
• https://osv.dev/vulnerability/CVE-2021-31921 · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2021-9396.html · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2021-9398.html · Vendor Advisory
• https://t.me/cvenotify/16338 · Telegram Post