I found out, that I can pass different data types (as argument), even if the Solidity method takes only uint data type, why is that possible?
Example:
function test (uint _param) public {
//do smth
}
test(address(ADDRESS_VAR))
Add a comment
|
1 Answer
There is no data type in the calldata. They are all coded as hexadecimal. So if you pass to the contract an address like this: 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D, EVM thinks, "ok, there is no problem. It is a number". Because you can convert it to uint: 697323163401596485410334513241460920685086001293.
-
1Thanks, I was asking this because I found out that I can maliciously modify state variables of a contract using a delegate call, even when it's a different type than what the function wants. This helped a lot, thanks!!– DavidJun 2, 2022 at 20:35
-
You're welcome! You are right, this method gives facilities in the delegatecall attacks. Because of that, anyone who uses delegatecall, he has to know what he is doing. Jun 3, 2022 at 7:22