passcode_WriteUp(pwnable.kr_passcode)scanf函数不加"&"带来的危险

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passcode_WriteUp(pwnable.kr_passcode)scanf函数不加”&”带来的危险

题目传送门：http://pwnable.kr/play.php

#include <stdio.h>
#include <stdlib.h>

void login(){
    int passcode1;
    int passcode2;

    printf("enter passcode1 : ");
    scanf("%d", passcode1);
    fflush(stdin);

    // ha! mommy told me that 32bit is vulnerable to bruteforcing :)
    printf("enter passcode2 : ");
        scanf("%d", passcode2);

    printf("checking...\n");
    if(passcode1==338150 && passcode2==13371337){
                printf("Login OK!\n");
                system("/bin/cat flag");
        }
        else{
                printf("Login Failed!\n");
        exit(0);
        }
}

void welcome(){
    char name[100];
    printf("enter you name : ");
    scanf("%100s", name);
    printf("Welcome %s!\n", name);
}

int main(){
    printf("Toddler's Secure Login System 1.0 beta.\n");

    welcome();
    login();

    // something after login...
    printf("Now I can safely trust you that you have credential :)\n");
    return 0;   
}

可以将源代码，可执行文件以scp -P 2222 [email protected]:/home/passcode/passcode.c passcode.c下载到本地分析

另外，由于我在网上找到了有大佬写过这个，而且写的很全面，觉得自己无需再次搬砖，就把大佬的链接放在这里了：https://blog.csdn.net/smalosnail/article/details/53247502