CVE-2021-39156

HIGH

Istio < 1.9.8 - Incorrect Authorization

Title source: rule

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.

Scores

CVSS v3 8.1
EPSS 0.0024
EPSS Percentile 46.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Classification

CWE
CWE-706 CWE-863
Status published

Affected Products (2)

istio/istio < 1.9.8
istio.io/istio < 1.9.8Go

Timeline

Published Aug 24, 2021
Tracked Since Feb 18, 2026