An attacker with elevated privileges can utilize Ansible functions to carry out actions as the Foreman-proxy user on the system. The prerequisite for this is that the hosts must have already been added to Foreman, and the attacker must have access to one of these hosts. If the attacker already has access to the system, they are deemed trustworthy with a high level of privilege.
Looke like foreman_ansible introduced REX and job_templates in foreman_ansible-2.0.0 onward. https://github.com/theforeman/foreman_ansible/commit/a5e0827bc3ec6c8ab82f968907857a15646305d5
The complexity of performing this attack is not within the attacker's control and privilege required evaluated is high. The administrator of Foreman must grant the attacker administrative-equivalent privileges to create or modify job templates (PR:H). However, even if the attacker has the necessary access, they still need to have at least two host machines deployed and added to Foreman, and have access to the first host to gain access to the second in order to achieve remote code execution on the machine (AC:H).