8.1
HIGH
CVE-2021-39156
Istio URI Path Bypass Authorization Vulnerability
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.

INFO

Published Date :

Aug. 24, 2021, 11:15 p.m.

Last Modified :

Nov. 7, 2023, 3:37 a.m.

Remotely Exploitable :

Yes !

Impact Score :

5.2

Exploitability Score :

2.8
Affected Products

The following products are affected by CVE-2021-39156 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Istio istio
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-39156.

URL Resource
https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r Third Party Advisory
https://istio.io/latest/news/security/istio-security-2021-008 Vendor Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-39156 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-39156 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Changed 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. 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.
  • Reanalysis by [email protected]

    Aug. 12, 2022

    Action Type Old Value New Value
    Removed CWE NIST CWE-863
    Added CWE NIST CWE-706
  • Initial Analysis by [email protected]

    Aug. 31, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:N/A:N)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    Changed Reference Type https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r No Types Assigned https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r Third Party Advisory
    Changed Reference Type https://istio.io/latest/news/security/istio-security-2021-008 No Types Assigned https://istio.io/latest/news/security/istio-security-2021-008 Vendor Advisory
    Added CWE NIST CWE-863
    Added CPE Configuration OR *cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:* versions up to (excluding) 1.9.8 *cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:* versions from (including) 1.10.0 up to (excluding) 1.10.3 *cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:* versions from (including) 1.11.0 up to (excluding) 1.11.1
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-39156 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.17 }} 0.02%

score

0.53063

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability