Can you please give your views on the following:
The structure of SAP is such that the privilege to create a user and to allocate the role/activity to perform any function is given through a single transaction code.
The inability to allocate roles and create users or resetting their passwords through two different channels (transaction codes) is a structural weakness within SAP which can only be addressed by the technical people of SAP AG.
Related: PFCG Roles and Authorization Concept
An ideal segregation would require these complementary functions to be performed by two different users. That is, the person who has the ability to create a user should not be allowed to assign the roles at the same time. Moreover, the fact that the structure of SAP enables any user to individually assign the roles without any other users interference does increase a inherent risk in SAP.
Moreover, based on the ideal security level the ability to allocate roles/transaction codes in SAP should not be such that it is executable by a user individually on his own.
A person who has SU01 or PFCG is, in reality, a super user. Can you suggest how to reduce the ability of the super user and especially the ability to individually assign roles to anyone, along with himself?
'm not an authorizations expert, but I assume that it should be possible to split authorization responsibilities. The same is possible with development and customizing. In most organizations, developers and customizers are allowed to do whatever they want in the development and acceptance system. The usage of the transport system is however limited and monitored by the approval concept. In such a setup, the SAP Basis administrator is responsible for transport management.
Security and Data Protection with SAP Systems, published by SAP-PRESS in 2001, has an interesting chapter on distribution of roles and authorization maintenance. Unfortunately, the authors limit themselves to the an explanation of the concept. The technical implementation is not discussed. The chapter more or less discusses the issue you are describing and a possible solution.