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geek01/xss_clean.php

Forked from mbijon/xss_clean.php
Last active January 12, 2016 07:34
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Revisions

  1. geek01 revised this gist Jan 12, 2016. 1 changed file with 4 additions and 1 deletion.
    5 changes: 4 additions & 1 deletion xss_clean.php
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    Original file line number Diff line number Diff line change
    @@ -1,3 +1,4 @@
    <?php
    /*
    * XSS filter
    *
    @@ -48,4 +49,6 @@ function xss_clean($data)

    // we are done...
    return $data;
    }
    }

    ?>
  2. @mbijon mbijon revised this gist Jul 21, 2011. 1 changed file with 5 additions and 0 deletions.
    5 changes: 5 additions & 0 deletions xss_clean.php
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    @@ -7,6 +7,11 @@
    * It was tested against *most* exploits here: http://ha.ckers.org/xss.html
    * WARNING: Some weren't tested!!!
    * Those include the Actionscript and SSI samples, or any newer than Jan 2011
    *
    *
    * TO-DO: compare to SymphonyCMS filter:
    * https://github.com/symphonycms/xssfilter/blob/master/extension.driver.php
    * (Symphony's is probably faster than my hack)
    */

    function xss_clean($data)
  3. @mbijon mbijon created this gist Jul 21, 2011.
    46 changes: 46 additions & 0 deletions xss_clean.php
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,46 @@
    /*
    * XSS filter
    *
    * This was built from numerous sources
    * (thanks all, sorry I didn't track to credit you)
    *
    * It was tested against *most* exploits here: http://ha.ckers.org/xss.html
    * WARNING: Some weren't tested!!!
    * Those include the Actionscript and SSI samples, or any newer than Jan 2011
    */

    function xss_clean($data)
    {
    // Fix &entity\n;
    $data = str_replace(array('&amp;','&lt;','&gt;'), array('&amp;amp;','&amp;lt;','&amp;gt;'), $data);
    $data = preg_replace('/(&#*\w+)[\x00-\x20]+;/u', '$1;', $data);
    $data = preg_replace('/(&#x*[0-9A-F]+);*/iu', '$1;', $data);
    $data = html_entity_decode($data, ENT_COMPAT, 'UTF-8');

    // Remove any attribute starting with "on" or xmlns
    $data = preg_replace('#(<[^>]+?[\x00-\x20"\'])(?:on|xmlns)[^>]*+>#iu', '$1>', $data);

    // Remove javascript: and vbscript: protocols
    $data = preg_replace('#([a-z]*)[\x00-\x20]*=[\x00-\x20]*([`\'"]*)[\x00-\x20]*j[\x00-\x20]*a[\x00-\x20]*v[\x00-\x20]*a[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iu', '$1=$2nojavascript...', $data);
    $data = preg_replace('#([a-z]*)[\x00-\x20]*=([\'"]*)[\x00-\x20]*v[\x00-\x20]*b[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iu', '$1=$2novbscript...', $data);
    $data = preg_replace('#([a-z]*)[\x00-\x20]*=([\'"]*)[\x00-\x20]*-moz-binding[\x00-\x20]*:#u', '$1=$2nomozbinding...', $data);

    // Only works in IE: <span style="width: expression(alert('Ping!'));"></span>
    $data = preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?expression[\x00-\x20]*\([^>]*+>#i', '$1>', $data);
    $data = preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?behaviour[\x00-\x20]*\([^>]*+>#i', '$1>', $data);
    $data = preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:*[^>]*+>#iu', '$1>', $data);

    // Remove namespaced elements (we do not need them)
    $data = preg_replace('#</*\w+:\w[^>]*+>#i', '', $data);

    do
    {
    // Remove really unwanted tags
    $old_data = $data;
    $data = preg_replace('#</*(?:applet|b(?:ase|gsound|link)|embed|frame(?:set)?|i(?:frame|layer)|l(?:ayer|ink)|meta|object|s(?:cript|tyle)|title|xml)[^>]*+>#i', '', $data);
    }
    while ($old_data !== $data);

    // we are done...
    return $data;
    }