Keycloak's device authorization grant does not correctly validate the device code and client ID. An attacker client could abuse the missing validation to spoof a client consent request and trick an authorization admin into granting consent to a malicious OAuth client or possible unauthorized access to an existing OAuth client.

A flaw was found in Keycloak. This issue may allow an attacker to steal authorization codes or tokens from clients using a wildcard in the JARM response mode "form_post.jwt" which could be used to bypass the security patch implemented to address CVE-2023-6134.

A flaw was found in Keycloak that prevents certain schemes in redirects, but permits them if a wildcard is appended to the token. This issue could allow an attacker to submit a specially crafted request leading to cross-site scripting (XSS) or further attacks. This flaw is the result of an incomplete fix for CVE-2020-10748.

An unconstrained memory consumption vulnerability was discovered in Keycloak. It can be triggered in environments which have millions of offline tokens (> 500,000 users with each having at least 2 saved sessions). If an attacker creates two or more user sessions and then open the "consents" tab of the admin User Interface, the UI attempts to load a huge number of offline client sessions leading to excessive memory and CPU consumption which could potentially crash the entire system.

A flaw was found in Undertow. When an AJP request is sent that exceeds the max-header-size attribute in ajp-listener, JBoss EAP is marked in an error state by mod_cluster in httpd, causing JBoss EAP to close the TCP connection without returning an AJP response. This happens because mod_proxy_cluster marks the JBoss EAP instance as an error worker when the TCP connection is closed from the backend after sending the AJP request without receiving an AJP response, and stops forwarding. This issue could allow a malicious user could to repeatedly send requests that exceed the max-header-size, causing a Denial of Service (DoS).

A flaw was found in Keycloak. A Keycloak server configured to support mTLS authentication for OAuth/OpenID clients does not properly verify the client certificate chain. A client that possesses a proper certificate can authorize itself as any other client, therefore, access data that belongs to other clients.

A flaw was found in undertow. Servlets annotated with @MultipartConfig may cause an OutOfMemoryError due to large multipart content. This may allow unauthorized users to cause remote Denial of Service (DoS) attack. If the server uses fileSizeThreshold to limit the file size, it's possible to bypass the limit by setting the file name in the request to null.

A reflected cross-site scripting (XSS) vulnerability was found in the 'oob' OAuth endpoint due to incorrect null-byte handling. This issue allows a malicious link to insert an arbitrary URI into a Keycloak error page. This flaw requires a user or administrator to interact with a link in order to be vulnerable. This may compromise user details, allowing it to be changed or collected by an attacker.

A flaw was found in Red Hat Single Sign-On for OpenShift container images, which are configured with an unsecured management interface enabled. This flaw allows an attacker to use this interface to deploy malicious code and access and modify potentially sensitive information in the app server configuration.

A flaw was found in the offline_access scope in Keycloak. This issue would affect users of shared computers more (especially if cookies are not cleared), due to a lack of root session validation, and the reuse of session ids across root and user authentication sessions. This enables an attacker to resolve a user session attached to a previously authenticated user; when utilizing the refresh token, they will be issued a token for the original user.