This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in Keycloak
A flaw was found in Keycloak. This flaw allows a privileged attacker to use the malicious payload as the group name while creating a new group from the admin console, leading to a stored Cross-site scripting (XSS) attack. (2022-08-26, CVE-2022-0225)
A POST based reflected Cross Site Scripting vulnerability on has been identified in Keycloak. (2022-03-25, CVE-2021-20323)
A flaw was found in keycloak. The new account console in keycloak can allow malicious code to be executed using the referrer URL. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (2021-03-23, CVE-2021-20222)
A flaw was found in Keycloak before version 12.0.0, where it is possible to add unsafe schemes for the redirect_uri parameter. This flaw allows an attacker to perform a Cross-site scripting attack. (2020-11-17, CVE-2020-10776)
A flaw was found in Keycloak's data filter, in version 10.0.1, where it allowed the processing of data URLs in some circumstances. This flaw allows an attacker to conduct cross-site scripting or further attacks. (2020-09-16, CVE-2020-10748)
It was found in all keycloak versions before 9.0.0 that links to external applications (Application Links) in the admin console are not validated properly and could allow Stored XSS attacks. An authed malicious user could create URLs to trick users in other realms, and possibly conduct further attacks. (2020-02-10, CVE-2020-1697)
A flaw was found in Keycloak 3.4.3.Final, 4.0.0.Beta2, 4.3.0.Final. When using 'response_mode=form_post' it is possible to inject arbitrary Javascript-Code via the 'state'-parameter in the authentication URL. This allows an XSS-Attack upon succesfully login. (2018-11-13, CVE-2018-14655)
Why Cross-site Scripting can be dangerous
Cross site scripting is an attack where a web page executes code that is injected by an adversary. It usually appears, when users input is presented. This attack can be used to impersonate a user, take over control of the session, or even steal API keys.
The attack can be executed e.g. when you application injects the request parameter directly into the HTML code of the page returned to the user:
https://server.com/confirmation?message=Transaction+Complete
what results in:
<span>Confirmation: Transaction Complete</span>
In that case the message can be modified to become a valid Javascript code, e.g.:
https://server.com/confirmation?message=<script>dangerous javascript code here</script>
and it will be executed locally by the user's browser with full access to the user's personal application/browser data:
<span>Confirmation: <script>dangerous javascript code here</script></span>