CVE-2023-6563 (GCVE-0-2023-6563)

Vulnerability from cvelistv5 – Published: 2023-12-14 18:01 – Updated: 2026-09-22 03:27
VLAI
Title
Keycloak: offline session token dos
Summary
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.
Severity
7.7 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
Impacted products
Vendor Product Version
Red Hat Red Hat Single Sign-On 7.6 for RHEL 7 Unaffected: 0:18.0.11-2.redhat_00003.1.el7sso , < * (rpm)
    cpe:/a:redhat:red_hat_single_sign_on:7.6::el7
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Red Hat Red Hat Single Sign-On 7.6 for RHEL 8 Unaffected: 0:18.0.11-2.redhat_00003.1.el8sso , < * (rpm)
    cpe:/a:redhat:red_hat_single_sign_on:7.6::el8
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Red Hat Red Hat Single Sign-On 7.6 for RHEL 9 Unaffected: 0:18.0.11-2.redhat_00003.1.el9sso , < * (rpm)
    cpe:/a:redhat:red_hat_single_sign_on:7.6::el9
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Red Hat RHEL-8 based Middleware Containers Unaffected: 7.6-38 , < * (rpm)
    cpe:/a:redhat:rhosemc:1.0::el8
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Red Hat RHEL-8 based Middleware Containers Unaffected: 7.6.6-2 , < * (rpm)
    cpe:/a:redhat:rhosemc:1.0::el8
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Red Hat Single Sign-On 7.6.6     cpe:/a:redhat:red_hat_single_sign_on:7.6
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Red Hat Red Hat Build of Keycloak     cpe:/a:redhat:build_keycloak:
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Date Public
2023-12-14 00:00
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.