Implementation
Before calling privileged APIs, always ensure that the assumptions made by the privileged code hold true prior to making the call.
Architecture and Design
Know architecture and implementation weaknesses of the privileged APIs and make sure to account for these weaknesses before calling the privileged APIs to ensure that they can be called safely.
Implementation
If privileged APIs make certain assumptions about data, context or state validity that are passed by the caller, the calling code must ensure that these assumptions have been validated prior to making the call.
Implementation
If privileged APIs do not shed their privilege prior to returning to the calling code, then calling code needs to shed these privileges immediately and safely right after the call to the privileged APIs. In particular, the calling code needs to ensure that a privileged thread of execution will never be returned to the user or made available to user-controlled processes.
Implementation
Only call privileged APIs from safe, consistent and expected state.