CVE-2021-20195: Input Validation

Published Jan 22, 2021
·
Updated

A flaw was found in keycloak in versions before 13.0.0. A Self Stored XSS attack vector escalating to a complete account takeover is possible due to user-supplied data fields not being properly encoded and Javascript code being used to process the data. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Other sources

The Keycloak server is vulnerable to a Self Stored XSS attack vector, which can be escalated to a complete account takeover using additional attack techniques as specified below. Specifically, the Account page does not HTML-encode the user first name, and last name, which means a malicious HTML code, which executes malicious Javascript code, can be embedded into the Account page. Even though the malicious Javascript code is linked to the attacker user (Self-XSS), it can be exploited on the Keycloak admin browser, using the Impersonation functionality, and thus, the attacker is able to compromise Keycloak.

https://issues.redhat.com/browse/KEYCLOAK-16890

Red Hat

Affected Software

2 affected componentsFixes available
redhat/keycloak<13.0.0
13.0.0
redhat Keycloak<12.0.3

Event History

Jan 22, 2021
Data Sourced
via Red Hat·08:56 AM
DescriptionSeverityAffected Software
May 28, 2021
CVE Published
via MITRE·10:42 AM
Data Sourced
via MITRE·10:42 AM
DescriptionWeakness

Frequently Asked Questions

1

What is CVE-2021-20195?

CVE-2021-20195 is a vulnerability found in Keycloak versions before 13.0.0, which allows for a Self Stored XSS attack vector that could lead to a complete account takeover.

2

What is the severity of CVE-2021-20195?

The severity of CVE-2021-20195 is critical with a CVSS score of 9.6.

3

How can the CVE-2021-20195 vulnerability be exploited?

The CVE-2021-20195 vulnerability can be exploited through a Self Stored XSS attack vector, where user-supplied data fields are not properly encoded and JavaScript code is used to process the data.

4

Which software versions are affected by CVE-2021-20195?

CVE-2021-20195 affects Keycloak versions before 13.0.0.

5

How do I mitigate the CVE-2021-20195 vulnerability?

To mitigate the CVE-2021-20195 vulnerability, it is recommended to update Keycloak to version 13.0.0 or later.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203