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. 21, 2024, 6:18 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 2.0 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Upgrade Istio to version 1.9.8, 1.10.4, or 1.11.1 or later.
- If an upgrade is not possible, consider implementing a Lua filter to normalize the request path as a workaround.
Public PoC/Exploit Available at Github
CVE-2021-39156 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
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 |
| 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 |
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)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-39156
weaknesses.
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).
All Public RunWhen Helm Charts - Managed by terraform
Smarty Shell Dockerfile
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 af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://github.com/istio/istio/security/advisories/GHSA-hqxw-mm44-gc4r Added Reference https://istio.io/latest/news/security/istio-security-2021-008 -
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
Vulnerability Scoring Details
Base CVSS Score: 8.1
Base CVSS Score: 5
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.29 }} 0.10%
score
0.52038
percentile