RHEL 6 : Red Hat Single Sign-On 7.4.9 security update on RHEL 6 (Moderate) (RHSA-2021:3527)

high Nessus Plugin ID 165141


The remote Red Hat host is missing one or more security updates for Red Hat Single Sign-On 7.4.9.


The remote Redhat Enterprise Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:3527 advisory.

Red Hat Single Sign-On 7.4 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 7.4.9 serves as a replacement for Red Hat Single Sign-On 7.4.8, and includes bug fixes and enhancements, which are documented in the Release Notes document linked to in the References.

Security Fix(es):

* jackson-dataformat-cbor: Unchecked allocation of byte buffer can cause a java.lang.OutOfMemoryError exception (CVE-2020-28491)

* keycloak: Brute force attack is possible even after the account lockout (CVE-2021-3513)

* keycloak: Anyone can register a new device when there is no device registered for passwordless login (CVE-2021-3632)

* keycloak-model-infinispan: authenticationSessions map in RootAuthenticationSessionEntity grows boundlessly could lead to a DoS attack (CVE-2021-3637)

* keycloak: X509 Direct Grant Auth does not verify certificate timestamp validity (CVE-2020-35509)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, 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.


Update the RHEL Red Hat Single Sign-On 7.4.9 package based on the guidance in RHSA-2021:3527.

See Also










Plugin Details

Severity: High

ID: 165141

File Name: redhat-RHSA-2021-3527.nasl

Version: 1.7

Type: local

Agent: unix

Published: 9/15/2022

Updated: 6/3/2024

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information


Risk Factor: Medium

Score: 5.9


Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2021-3637


Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS Score Source: CVE-2021-3632

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:rh-sso7-keycloak, p-cpe:/a:redhat:enterprise_linux:rh-sso7-keycloak-server, cpe:/o:redhat:enterprise_linux:6

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 9/14/2021

Vulnerability Publication Date: 2/18/2021

Reference Information

CVE: CVE-2020-28491, CVE-2020-35509, CVE-2021-3513, CVE-2021-3632, CVE-2021-3637

CWE: 20, 287, 400, 522, 770

RHSA: 2021:3527