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


extern char** environ;

void vuln(char *arg)
{
        char msg[12];
        strcpy(msg,arg);
}

int main(int argc, char** argv)
{
	int n=0;

        for (n = 0;  environ[n] != NULL;  ++n)
	{
		memset(environ[n], 0, strlen(environ[n]));
		environ[n] = NULL;
	}


	if (argc != 2)
	{
		printf("Usage : prog arg\n");
		exit(1);
	}

	vuln(argv[1]);


	return 0;
}