CVE-2021-39156: istio Incorrect Authorization

Vulnerability summary

CVE-2021-39156 is a high (CVSS 8.1) Incorrect Authorization vulnerability in istio. EPSS estimates a 1.18% chance of exploitation in the next 30 days, higher than 67.1% of scored vulnerabilities.

Timeline

1. 24-08-2021
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

Istio is an open source platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with `#fragment` in the path may bypass Istio’s URI path based authorization policies. Patches are available in Istio 1.11.1, Istio 1.10.4 and Istio 1.9.8. As a work around a Lua filter may be written to normalize the path.

• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
• CWE-706Use of Incorrectly-Resolved Name or ReferenceThe product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.