CVE-2023-6563

Public Exploit
Keycloak: offline session token dos

Description

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.

Remediation

Workaround:

  • There are three main options to prevent exploitation: 1) If you are using a reverse proxy, block the consents URL. 2) This option is less effective: remove the consents application tab from the account console theme. 3) This option has a significant negative impact on end users: entirely disable offline user profiles.

Category

7.7
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.30%
Vendor Advisory redhat.com Vendor Advisory redhat.com Vendor Advisory redhat.com Vendor Advisory redhat.com Vendor Advisory redhat.com Vendor Advisory redhat.com
Affected: Red Hat Red Hat Single Sign-On 7.6 for RHEL 7
Affected: Red Hat Red Hat Single Sign-On 7.6 for RHEL 8
Affected: Red Hat Red Hat Single Sign-On 7.6 for RHEL 9
Affected: Red Hat RHEL-8 based Middleware Containers
Affected: Red Hat RHEL-8 based Middleware Containers
Affected: Red Hat Single Sign-On 7.6.6
Affected: Red Hat Red Hat Build of Keycloak
Published at:
Updated at:

References

Link Tags
https://access.redhat.com/errata/RHSA-2023:7854 vendor advisory
https://access.redhat.com/errata/RHSA-2023:7855 vendor advisory
https://access.redhat.com/errata/RHSA-2023:7856 vendor advisory
https://access.redhat.com/errata/RHSA-2023:7857 vendor advisory exploit
https://access.redhat.com/errata/RHSA-2023:7858 vendor advisory
https://access.redhat.com/security/cve/CVE-2023-6563 vdb entry vendor advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2253308 issue tracking
https://github.com/keycloak/keycloak/issues/13340 issue tracking

Frequently Asked Questions

What is the severity of CVE-2023-6563?
CVE-2023-6563 has been scored as a high severity vulnerability.
How to fix CVE-2023-6563?
As a workaround for remediating CVE-2023-6563: There are three main options to prevent exploitation: 1) If you are using a reverse proxy, block the consents URL. 2) This option is less effective: remove the consents application tab from the account console theme. 3) This option has a significant negative impact on end users: entirely disable offline user profiles.
Is CVE-2023-6563 being actively exploited in the wild?
It is possible that CVE-2023-6563 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-6563?
CVE-2023-6563 affects Red Hat Red Hat Single Sign-On 7.6 for RHEL 7, Red Hat Red Hat Single Sign-On 7.6 for RHEL 8, Red Hat Red Hat Single Sign-On 7.6 for RHEL 9, Red Hat RHEL-8 based Middleware Containers, Red Hat RHEL-8 based Middleware Containers, Red Hat Single Sign-On 7.6.6, Red Hat Red Hat Build of Keycloak.
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