Best practice for securing web API endpoint

Say, I am working for a bank that lets users use a mobile app. I am a developer working on the mobile app for that bank. The app gets OAuth access token and access a web API hosted by the bank. The app has been released.

A regular user who has a valid account in the bank installs the mobile app. Through the mobile app, the user can view the balance, transfer money, etc.

This user has a dev skill and noticed that he can get the access token after he signs in to the bank with his user name and password.

Because this user has a valid account for the bank, the access token is valid to call the API endpoints. The user does trial and error in his Visual Studio to figure out what requests need to be sent to get a valid response from the API. He can refresh access token as many times as needed with the official mobile app manually and eventually finds a way to make valid calls against the API from his dev tool.

Question is, are there any mechanisms that can be utilized to prevent the user from calling the endpoint without going through the official mobile app? The web API can be marked with [RequiredScope] attribute, for example, but if he was able to sign in, should he have all the permissions to do what the normal users are allowed to do, such as transferring money?

I have done searches on this topic on the web as it seems to be a common topic, but have not found references yet.

Read answers here.

Resources

https://learn.microsoft.com/en-us/aspnet/core/security/authorization/secure-data?view=aspnetcore-6.0

FavoriteLoadingAdd to favorites
Spread the love

Author: Shahzad Khan

Software developer / Architect