CVE-2020-16844

istio: incorrect translation of DENY policy for TCP service

Severity Score

6.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

In Istio 1.5.0 though 1.5.8 and Istio 1.6.0 through 1.6.7, when users specify an AuthorizationPolicy resource with DENY actions using wildcard suffixes (e.g. *-some-suffix) for source principals or namespace fields, callers will never be denied access, bypassing the intended policy.

En Istio versiones 1.5.0 hasta 1.5.8 e Istio versiones 1.6.0 hasta 1.6.7, cuando los usuarios especifican un recurso AuthorizationPolicy con acciones DENY usando sufijos de comodín (por ejemplo, *-some-suffix) para los campos source principals o namespace, a los que llaman nunca se le denegará el acceso, omitiendo la política prevista

An insecure access control vulnerability was found in Istio. If an authorization policy is created for a TCP service that includes a DENY rule with a prefix wildcard, Istio translates this into an Envoy string match, incorrectly removing the wildcard. This flaw allows an attacker to subvert particular DENY rules, potentially gaining access to restricted resources.

*Credits: N/A

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

Single

Confidentiality

Partial

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-08-04 CVE Reserved
2020-08-11 CVE Published
2024-02-04 EPSS Updated
2024-08-04 CVE Updated
2024-08-04 First Exploit
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-284: Improper Access Control

CAPEC

References (4)

URL	Tag	Source

URL	Date	SRC
https://istio.io/latest/news/security/istio-security-2020-009	2024-08-04

URL	Date	SRC

URL	Date	SRC
https://github.com/istio/istio/releases	2020-10-15
https://access.redhat.com/security/cve/CVE-2020-16844	2020-08-11
https://bugzilla.redhat.com/show_bug.cgi?id=1861625	2020-08-11

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Istio Search vendor "Istio"		Istio Search vendor "Istio" for product "Istio"				>= 1.5.0 <= 1.5.8 Search vendor "Istio" for product "Istio" and version " >= 1.5.0 <= 1.5.8"		-		Affected
Istio Search vendor "Istio"		Istio Search vendor "Istio" for product "Istio"				>= 1.6.0 <= 1.6.7 Search vendor "Istio" for product "Istio" and version " >= 1.6.0 <= 1.6.7"		-		Affected