A flaw was found in Keycloak. A remote attacker with administrative privileges, specifically those with manage-client permission or access to client registration endpoints, could bypass client Uniform Resource Identifier (URI) validation. This is achieved by registering a malicious client with a specially crafted redirect URI using a case-insensitive javascript: or data: scheme. This Cross-Site Scripting (XSS) vulnerability allows for arbitrary code execution in the Keycloak origin when a victim clicks the crafted link, such as in the logout flow or the Admin Console.
Exploitability
AV:NAC:LPR:LUI:RScope
S:UImpact
C:HI:HA:N7.3/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:NInjection