Mastering Blockchain Programming with Solidity

Avoid dependency on untrusted external calls

As we have discussed, there are some contracts or services that are managed by an external third party. The risk in calling an external function on these services is very high. Our external function calls are dependent on their contract and code, and hence it might be possible for these external services to inject malicious code; if executed, your contracts would behave unexpectedly. It is always recommended to have fewer untrusted external function calls.

Ensure that enough due diligence is done while choosing an external contract for integration with your contracts.