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CVE-2023-6563

Redhat Keycloak denial of service

7.7 HIGHPublic exploitEPSS 1.24%
  1. Published14 Dec 2023

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredLow
User interactionNone
ScopeChanged
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Affected products

Redhat Keycloak< 21.0.0
Redhat Openshift Container Platform4.11 · 4.12
Redhat Openshift Container Platform For Ibm Linuxone4.10 · 4.9
Redhat Openshift Container Platform For Power4.10 · 4.9
Redhat Single Sign-on7.6

Remediation

Fixed in
Redhat Keycloak≥ 21.0.0

References

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Frequently asked

Is CVE-2023-6563 being actively exploited?

CVE-2023-6563 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 1.24%.

How severe is CVE-2023-6563?

CVE-2023-6563 has a CVSS 3.1 base score of 7.7, rated high. EPSS estimates a 1.24% probability of exploitation.

Which products are affected by CVE-2023-6563?

Affected products include Redhat Keycloak, Redhat Openshift Container Platform, Redhat Openshift Container Platform For Ibm Linuxone, Redhat Openshift Container Platform For Power, Redhat Single Sign-on.

How do I fix CVE-2023-6563?

Upgrade affected software to a fixed version, for example Redhat Keycloak 21.0.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2023-6563 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.