CVSS8.8
Severityhigh
WeaknessCWE-843
ExploitedNot in CISA KEV
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Description
A flaw was found in Keycloak's Dynamic Client Registration (DCR) security policy management. The "Allowed Protocol Mapper Types" policy, which restricts which types of data mappers a client can use, fails to re-validate the mapper type during a client update if the mapper's configuration remains unchanged. An attacker with client registration privileges can exploit this by first registering an allowed mapper type with a malicious configuration and then swapping it for a restricted, high-privilege mapper type (such as one that hardcodes administrative roles). This allows the attacker to gain full administrative access to the Keycloak realm.