Anti XSS Filter PHP

[nickymonsma]

Spoiler:

<?php
ob_start("ob_gzhandler");

foreach($_GET as $key => $value){
$_GET[$key]=mysql_real_escape_string(stripslashes(trim(htmlspecialchars($value))));
}
foreach($_POST as $key => $value){
$_POST[$key]=mysql_real_escape_string(stripslashes(trim(htmlspecialchars($value))));
}
foreach($_REQUEST as $key => $value){
$_REQUEST[$key]=mysql_real_escape_string(stripslashes(trim(htmlspecialchars($value))));
}

function RemoveXSS($val)
{
$val = preg_replace('/([\x00-\x08,\x0b-\x0c,\x0e-\x19])/', '', $val);

$search = '[a-zA-Z0-9]';
$search .= '!@#$%^&*()';
$search .= '~`";:?+/={}[]-\\_|\'';
for ($i = 0; $i < strlen($search); $i++)
{
$val = preg_replace('/(&#[xX]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val); // with a ;
$val = preg_replace('/(&#0{0,8}'.ord($search[$i]).';?)/', $search[$i], $val); // with a ;
}
$ra1 = Array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');
$ra2 = Array('onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavailable', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterchange', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowenter', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload');
$ra = array_merge($ra1, $ra2);

$found = true;
while ($found)
{
$val_before = $val;
for ($i = 0; $i < sizeof($ra); $i++)
{
$pattern = '/';
for ($j = 0; $j < strlen($ra[$i]); $j++)
{
if ($j > 0)
{
$pattern .= '(';
$pattern .= '(&#[xX]0{0,8}([9ab]);)';
$pattern .= '|';
$pattern .= '|(&#0{0,8}([9|10|13]);)';
$pattern .= ')*';
}
$pattern .= $ra[$i][$j];
}
$pattern .= '/i';
$replacement = substr($ra[$i], 0, 2).'<x>'.substr($ra[$i], 2);
$val = preg_replace($pattern, $replacement, $val);
if ($val_before == $val)
{
$found = false;
}
}
}
return $val;
}
?>

Hope you like it :D

[MentaL]

[Droppy]

Niiiiice! 10/10.
And security... 10000000 :P

But an example of how a page in common!

(Sorry for my BAAD english, I am using Google Translator :P

[nickymonsma]

make an php include? its simple

[mohje]

thank you , interesting ^^

[nickymonsma]

No Problem you welcome

[Kaan2106]

and where to include it? -> index / me ..? More infos please - thank you ;3

[Shredinator]

and where to include it? -> index / me ..? More infos please - thank you ;3

Including it isn't enough, since RemoveXSS is a function.

[leenster]

make an php include? its simple

Maybe i am missing something but simply including this will only filter the GET's and POST'S

The function RemoveXSS($val) will just sit there and do nothing...


you need to add a call to that function.

Including it isn't enough, since RemoveXSS is a function.

I guess we started typing at the same time :)


Anyways, you(OP) better fix it before people start using it and think they are all safe now..

Something like this is how it should be used...

//UNTESTED//
$_SERVER['REQUEST_URI']=RemoveXXS($_SERVER['REQUEST_URI']); 

So simply including it is no good...

[nickymonsma]

Maybe i am missing something but simply including this will only filter the GET's and POST'S

The function RemoveXSS($val) will just sit there and do nothing...


you need to add a call to that function.



I guess we started typing at the same time :)


Anyways, you(OP) better fix it before people start using it and think they are all safe now..

Something like this is how it should be used...

//UNTESTED//
$_SERVER['REQUEST_URI']=RemoveXXS($_SERVER['REQUEST_URI'];) 

So simply including it is no good...

Oh Thanks :P

[leenster]

It is a typo3 script that he has edited.

[pepijndut]

I don't know what XSS is precisly (I know its anything with security) but i think you can better do this

<?php
ob_start("ob_gzhandler");

foreach($_GET as $key => $value){
$_GET[$key]=RemoveXSS(mysql_real_escape_string(stripslashes(trim(htmlspecialchars($value)))));
}
foreach($_POST as $key => $value){
$_POST[$key]=RemoveXSS(mysql_real_escape_string(stripslashes(trim(htmlspecialchars($value)))));
}
foreach($_REQUEST as $key => $value){
$_REQUEST[$key]=RemoveXSS(mysql_real_escape_string(stripslashes(trim(htmlspecialchars($value)))));
} 

function RemoveXSS($val) 
{
$val = preg_replace('/([\x00-\x08,\x0b-\x0c,\x0e-\x19])/', '', $val);

$search = '[a-zA-Z0-9]';
$search .= '!@#$%^&*()';
$search .= '~`";:?+/={}[]-\\_|\'';
for ($i = 0; $i < strlen($search); $i++) 
{
$val = preg_replace('/(&#[xX]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val); // with a ;
$val = preg_replace('/(&#0{0,8}'.ord($search[$i]).';?)/', $search[$i], $val); // with a ;
}
$ra1 = Array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');
$ra2 = Array('onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavailable', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterchange', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowenter', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload');
$ra = array_merge($ra1, $ra2);

$found = true;
while ($found) 
{
$val_before = $val;
for ($i = 0; $i < sizeof($ra); $i++) 
{
$pattern = '/';
for ($j = 0; $j < strlen($ra[$i]); $j++) 
{
if ($j > 0) 
{
$pattern .= '(';
$pattern .= '(&#[xX]0{0,8}([9ab]);)';
$pattern .= '|';
$pattern .= '|(&#0{0,8}([9|10|13]);)';
$pattern .= ')*';
}
$pattern .= $ra[$i][$j];
}
$pattern .= '/i';
$replacement = substr($ra[$i], 0, 2).'<x>'.substr($ra[$i], 2);
$val = preg_replace($pattern, $replacement, $val);
if ($val_before == $val) 
{
$found = false;
}
}
}
return $val;
} 
?>

[azaidi]

I don't know what XSS is precisly (I know its anything with security) but i think you can better do this

<?php
ob_start("ob_gzhandler");

foreach($_GET as $key => $value){
$_GET[$key]=RemoveXSS(mysql_real_escape_string(stripslashes(trim(htmlspecialchars($value)))));
}
foreach($_POST as $key => $value){
$_POST[$key]=RemoveXSS(mysql_real_escape_string(stripslashes(trim(htmlspecialchars($value)))));
}
foreach($_REQUEST as $key => $value){
$_REQUEST[$key]=RemoveXSS(mysql_real_escape_string(stripslashes(trim(htmlspecialchars($value)))));
}

function RemoveXSS($val)
{
$val = preg_replace('/([\x00-\x08,\x0b-\x0c,\x0e-\x19])/', '', $val);

$search = '[a-zA-Z0-9]';
$search .= '!@#$%^&*()';
$search .= '~`";:?+/={}[]-\\_|\'';
for ($i = 0; $i < strlen($search); $i++)
{
$val = preg_replace('/(&#[xX]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val); // with a ;
$val = preg_replace('/(�{0,8}'.ord($search[$i]).';?)/', $search[$i], $val); // with a ;
}
$ra1 = Array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');
$ra2 = Array('onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavailable', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterchange', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowenter', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload');
$ra = array_merge($ra1, $ra2);

$found = true;
while ($found)
{
$val_before = $val;
for ($i = 0; $i < sizeof($ra); $i++)
{
$pattern = '/';
for ($j = 0; $j < strlen($ra[$i]); $j++)
{
if ($j > 0)
{
$pattern .= '(';
$pattern .= '(&#[xX]0{0,8}([9ab]);)';
$pattern .= '|';
$pattern .= '|(�{0,8}([9|10|13]);)';
$pattern .= ')*';
}
$pattern .= $ra[$i][$j];
}
$pattern .= '/i';
$replacement = substr($ra[$i], 0, 2).'<x>'.substr($ra[$i], 2);
$val = preg_replace($pattern, $replacement, $val);
if ($val_before == $val)
{
$found = false;
}
}
}
return $val;
}
?>

Thats SQL injection, we're talking about XSS bro.

[pepijndut]

Owh okay.. What is XSS :P
I don't know anything about security xD

Pepijn =D

[nickymonsma]

XSS is Scripting - Alert() you know?

[Kaan2106]

XSS is Scripting - Alert() you know?

and this is what (Alert() ) explain sth ^^