Lord of Bof bugbear -> giant

/*
        The Lord of the BOF : The Fellowship of the BOF
        - giant
        - RTL2
*/

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

main(int argc, char *argv[])
{
    char buffer[40];
    FILE *fp;
    char *lib_addr, *execve_offset, *execve_addr;
    char *ret;

    if(argc < 2){
        printf("argv error\n");
        exit(0);
    }

    // gain address of execve
    fp = popen("/usr/bin/ldd /home/giant/assassin | /bin/grep libc | /bin/awk '{print $4}'", "r");
    fgets(buffer, 255, fp);
    sscanf(buffer, "(%x)", &lib_addr);
    fclose(fp);

    fp = popen("/usr/bin/nm /lib/libc.so.6 | /bin/grep __execve | /bin/awk '{print $1}'", "r");
    fgets(buffer, 255, fp);
    sscanf(buffer, "%x", &execve_offset);
    fclose(fp);

    execve_addr = lib_addr + (int)execve_offset;
    // end

    memcpy(&ret, &(argv[1][44]), 4);
    if(ret != execve_addr)
    {
        printf("You must use execve!\n");
        exit(0);
    }

    strcpy(buffer, argv[1]);
    printf("%s\n", buffer);
}