CVE-2021-4133: High severity redhat Keycloak vulnerability

Published Dec 16, 2021

Updated

A flaw was found in Keycloak in versions from 12.0.0 and before 15.1.1 which allows an attacker with any existing user account to create new default user accounts via the administrative REST API even when new user registration is disabled.

Other sources

A flaw was found in Keycloak version from 12.0.0 and before 15.1.1 which allows an attacker with any existing user account to create new default user accounts via the administrative REST API even when new user registration is disabled.

A incorrect authorization flaw was found in Keycloak 12.0.0 and greater as well as Red Hat Single Sign-On 7.5.0 and greater, the flaw allows an attacker with any existing user account to create new default user accounts via the administrative REST API even where new user registration is disabled.

— Red Hat

Affected Software

8 affected componentsFixes available

redhat/rh-sso7-keycloak<0:15.0.2-3.redhat_00002.1.el7

0:15.0.2-3.redhat_00002.1.el7

redhat/rh-sso7-keycloak<0:15.0.4-1.redhat_00001.1.el7

0:15.0.4-1.redhat_00001.1.el7

redhat/rh-sso7-keycloak<0:15.0.2-3.redhat_00002.1.el8

0:15.0.2-3.redhat_00002.1.el8

redhat/rh-sso7-keycloak<0:15.0.4-1.redhat_00001.1.el8

0:15.0.4-1.redhat_00001.1.el8

redhat/redhat-sso<7-sso75-openshift-rhel8

7-sso75-openshift-rhel8

redhat Keycloak>=12.0.0<15.1.1

redhat/keycloak<15.1.1

15.1.1

redhat/keycloak<16.0.0

16.0.0

Remediation

Information

Access to the user-creation functionality in the REST endpoint can be deactivated using CLI commands in undertow. run: bin/jboss-cli.sh --connect /subsystem=undertow/configuration=filter/expression-filter=keycloakPathOverrideUsersCreateEndpoint:add( \ expression="(regex('^/auth/admin/realms/(.*)/users$') and method(POST))-> response-code(400)" \ ) /subsystem=undertow/server=default-server/host=default-host/filter-ref=keycloakPathOverrideUsersCreateEndpoint:add()

Event History

Dec 16, 2021

CVE Published

05:05 PM

Dec 17, 2021

Data Sourced

via Red Hat·11:43 AM

DescriptionSeverityAffected Software

Jan 25, 2022

CVE Published

via MITRE·07:11 PM

Data Sourced

via MITRE·07:11 PM

DescriptionWeakness

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

What is CVE-2021-4133?

CVE-2021-4133 is a vulnerability found in Keycloak versions from 12.0.0 and before 15.1.1.

What is the severity of CVE-2021-4133?

The severity of CVE-2021-4133 is high with a CVSS score of 8.3.

How does CVE-2021-4133 impact Keycloak?

CVE-2021-4133 allows an attacker with any existing user account to create new default user accounts via the administrative REST API even when new user registration is disabled.

How can I fix CVE-2021-4133?

To fix CVE-2021-4133, it is recommended to upgrade Keycloak to version 15.1.1 or above.

Where can I find more information about CVE-2021-4133?

You can find more information about CVE-2021-4133 on the Red Hat Security Advisory RHSA-2021:5217 and RHSA-2021:5219.