Sorry if the title is a bit obscure, I didn't know what to call this. I recently got into mod making and thought of a mod which is able to control Spotify through in-game commands, using Spotify's API to do so. However, most of the games I found which support mods (WoW through addons and Skyrim and Fallout 4 through Creation Kit) don't allow you to perform requests or even communicate with external applications. I wanted to ask why game developers perform this practice, specifically what problems can arise if the user is permitted to perform requests through the internet or communicate to external applications?
Apart from cheating:
Most of the times, mods are installed without thorough review regarding trustworthiness of the creator (who can be anyone, as opposed to a studio), so it would not be a surprise if people were to use this vector to get malicious code executed on the victims computer. Now if the code then can not under any circumstance communicate with the outside world, there is nothing to be gained from such an attack (without further, far more complicated exploits).
This comes on top of that many games with a patching functionality are executed with admin privileges, meaning that such an attack would immediately have heightened permissions.
Tl;dr: is would be a far too easy and exploitable security vulnerability.