Kirby is a CMS targeting designers and editors. Kirby allows to restrict the permissions of specific user roles. Users of that role can only perform permitted actions. Permissions for creating and deleting languages have already existed and could be configured, but were not enforced by Kirby's frontend or backend code. A permission for updating existing languages has not existed before the patched versions. So disabling the languages.* wildcard permission for a role could not have prohibited updates to existing language definitions. The missing permission checks allowed attackers with Panel access to manipulate the language definitions. The problem has been patched in Kirby 3.6.6.6, Kirby 3.7.5.5, Kirby 3.8.4.4, Kirby 3.9.8.2, Kirby 3.10.1.1, and Kirby 4.3.1. Please update to one of these or a later version to fix the vulnerability. There are no known workarounds for this vulnerability.
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.