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.

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2023:7855 advisory.

    Red Hat Single Sign-On 7.6 is a standalone server, based on the Keycloak project, that provides     authentication and standards-based single sign-on capabilities for web and mobile applications.

    This release of Red Hat Single Sign-On 7.6.6 on RHEL 9 serves as a replacement for Red Hat Single Sign-On     7.6.5, and includes bug fixes and enhancements.

    Security Fix(es):
    * keycloak: redirect_uri validation logic that allows for a bypass of otherwise explicitly allowed hosts     (CVE-2023-6134)
    * keycloak: reflected XSS via wildcard in OIDC redirect_uri (CVE-2023-6291)
    * keycloak: offline session token DoS (CVE-2023-6563)

    For more details about the security issue(s), including the impact, a CVSS score, and other related     information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2023:7854 advisory.

    Red Hat Single Sign-On 7.6 is a standalone server, based on the Keycloak project, that provides     authentication and standards-based single sign-on capabilities for web and mobile applications.

    This release of Red Hat Single Sign-On 7.6.6 on RHEL 7 serves as a replacement for Red Hat Single Sign-On     7.6.5, and includes bug fixes and enhancements.

    Security Fix(es):
    * keycloak: reflected XSS via wildcard in OIDC redirect_uri (CVE-2023-6291)
    * keycloak: redirect_uri validation logic that allows for a bypass of otherwise explicitly allowed hosts     (CVE-2023-6134)
    * keycloak: offline session token DoS (CVE-2023-6563)

    For more details about the security issue(s), including the impact, a CVSS score, and other related     information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2023:7856 advisory.

    Red Hat Single Sign-On 7.6 is a standalone server, based on the Keycloak project, that provides     authentication and standards-based single sign-on capabilities for web and mobile applications.

    This release of Red Hat Single Sign-On 7.6.6 on RHEL 8 serves as a replacement for Red Hat Single Sign-On     7.6.5, and includes bug fixes and enhancements.

    Security Fix(es):
    * keycloak: reflected XSS via wildcard in OIDC redirect_uri (CVE-2023-6291)
    * keycloak: redirect_uri validation logic that allows for a bypass of otherwise explicitly allowed hosts     (CVE-2023-6134)
    * keycloak: offline session token DoS (CVE-2023-6563)

    For more details about the security issue(s), including the impact, a CVSS score, and other related     information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
186940	RHEL 9 : Red Hat Single Sign-On 7.6.6 security update on RHEL 9 (Important) (RHSA-2023:7855)	Nessus	Red Hat Local Security Checks	high
186938	RHEL 7 : Red Hat Single Sign-On 7.6.6 security update on RHEL 7 (Important) (RHSA-2023:7854)	Nessus	Red Hat Local Security Checks	high
186929	RHEL 8 : Red Hat Single Sign-On 7.6.6 security update on RHEL 8 (Important) (RHSA-2023:7856)	Nessus	Red Hat Local Security Checks	high

Detections

Analytics

CVE-2023-6563

high

Tenable Plugins

high

high

high