CVE-2023-6563

2023-12-1418:15:45

Google

osv.dev

keycloak

memory consumption

offline tokens

vulnerability

cpu consumption

admin ui

system crash

cve-2023-6563

7.7 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

7.4 High

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

39.6%

JSON

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.