CVE-2023-6563
Keycloak: offline session token dos
- Published
- Updated
- Reserved
- Assigned by
- redhat
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | High7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 1.2% · top 31% of all CVEs (5 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.7.
Weakness
Affected products
Red Hat · Red Hat Single Sign-On 7.6 for RHEL 7
- unaffected 0:18.0.11-2.redhat_00003.1.el7sso – < *
Red Hat · Red Hat Single Sign-On 7.6 for RHEL 8
- unaffected 0:18.0.11-2.redhat_00003.1.el8sso – < *
Red Hat · Red Hat Single Sign-On 7.6 for RHEL 9
- unaffected 0:18.0.11-2.redhat_00003.1.el9sso – < *
Red Hat · RHEL-8 based Middleware Containers
- unaffected 7.6-38 – < *
Red Hat · RHEL-8 based Middleware Containers
- unaffected 7.6.6-2 – < *
Red Hat · Single Sign-On 7.6.6
All versions: unaffected
Red Hat · Red Hat Build of Keycloak
All versions: unaffected
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.keycloak:keycloak-model-jpaGHSA-54f3-c6hg-865h (opens in a new tab)
What to do
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.
References (8)
- RHSA-2023:7854 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2023:7855 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2023:7856 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2023:7857 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2023:7858 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- https://access.redhat.com/security/cve/CVE-2023-6563 (opens in a new tab)vdb-entryx_refsource_REDHATx_transferred
- RHBZ#2253308 (opens in a new tab)issue-trackingx_refsource_REDHATx_transferred
- https://github.com/keycloak/keycloak/issues/13340 (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-54f3-c6hg-865h (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2023-6563)Record last updated .