Revive Old Post < 6.9.4 - Privilege Escalation

Description

Leveraging a publicly accessible AJAX function named ‘update_response’, it is possible to update any option with the WordPress installation. Using this vulnerability, it is possible to gain administrative access to the WordPress installation by updating the options ‘default_role’ and ‘users_can_register’, and then creating a new account. This new account will be created with administrative privileges, so long as these two options are updated to the values, as shown in the PoC below.