Azure subscriptions with custom roles are overly permissive TF-S1039

Subscription ownership should not include permission to create custom owner roles. One should follow the principle of least privilege and only necessary privileges be assigned instead of allowing full administrative access. Classic subscription admin roles offer basic access management, including Account Administrator, Service Administrator, and Co-Administrators. The minimum permissions necessary to be given to subscription owner accounts are recommended initially. Permissions can be added as needed by the account holder ensuring the account holder cannot perform non-intended actions.