Predicting V8’s Math.random() truncated outputs

Predicting V8’s Math.random() truncated outputs

i'm doing a research & working around Math.random() like a month ago. Math.random() uses XORSHIFT128+, so, if we can get the state of the PRNG, it'll be easy to predict future outputs.

It is public knowledge that Math.random() isn't a CSPRNG, quoting Mozilla's JS References :

Note: Math.random() does not provide cryptographically secure random numbers. Do not use them for anything related to security.

Anyways, we all know we can guess Math.random() future outputs by getting 3-4 consecutive outputs.

Here's a github repo about that -> https://github.com/PwnFunction/v8-randomness-predictor/tree/main

And here's another repo about the same topic (This even doesn't need consecutive outputs)

At this point, everything is very nice, but when we come to the Practical & Real world aspect, the things get really hard. In a practical scenario, the app's don't leak raw Math.random() outputs, right?

Let's imagine we have a NodeJS back-end that generates "random" numbers in a specific range with this function :

function RandomInt(min, max) {
    let res = Math.floor(Math.random() * (max - min + 1)) + min;
    return res;
}

After defining that function, let's suppose the server uses that function like this and retrieves the data to the client :

//Let's generate some random values in different ranges
var randomValuesTest = {
    randomVal1:RandomInt(250,300),  
    randomVal2:RandomInt(0,900),
    randomVal3:RandomInt(300,500),  
    randomVal4:RandomInt(0,800),    
    randomVal5:RandomInt(500,900),  
    randomVal6:RandomInt(0,800),    
    randomVal7:RandomInt(0,900) 
};

return randomValuesTest;

After googling three consecutive days, i just reached a guy that made a work-around for this using Python and Z3

I have zero Python knowledge, i tried to adapt the code but i haven't achieved it. So i come with a variety of questions and problems:

How i can adapt this script to solve this kind of problem?

Thanks for everything.