https://github.com/code-423n4/2024-08-superposition/blob/4528c9d2dbe1550d2660dac903a8246076044905/pkg/sol/OwnershipNFTs.sol#L160-L163
The approve function allows operator and owner to approve themselves to spend the token. This can be used to give themselves a backdoor to the token. If for example the operators status is to be revoked, he can always call the approve function on the token, to approve himself to spend the token. So even if his operator status is revoked, he still has access to the tokens.
Ensure that the owner/operator cannot approve themselves to spend a token.
