Question

I have inserted a hidden input in my comment form:

$ip = $_SERVER['REMOTE_ADDR'];
<input type="hidden" name="c-ip" value="<?php echo $ip; ?>">

Query :

$cname = removeXSS(mysql_real_escape_string($_post['c-name']));
.
.
.
$sql = "INSERT INTO guestbook (id, date, name, email, comment, ip, status) VALUES (' ', NOW(), '$cname', '$cemail', '$ctext' , '$cip', ' ') ";

function RemoveXSS($val) {
 // remove all non-printable characters. CR(0a) and LF(0b) and TAB(9) are allowed
 // this prevents some character re-spacing such as <java\0script>
 // note that you have to handle splits with \n, \r, and \t later since they *are*   allowed in some inputs
 $val = preg_replace('/([\x00-\x08,\x0b-\x0c,\x0e-\x19])/', '', $val);

// straight replacements, the user should never need these since they're normal characters
// this prevents like <IMG SRC=&#X40&#X61&#X76&#X61&#X73&#X63&#X72&#X69&#X70&#X74&#X3A &#X61&#X6C&#X65&#X72&#X74&#X28&#X27&#X58&#X53&#X53&#X27&#X29>
$search = 'abcdefghijklmnopqrstuvwxyz';
$search .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$search .= '1234567890!@#$%^&*()';
$search .= '~`";:?+/={}[]-_|\'\\';
for ($i = 0; $i < strlen($search); $i++) {
  // ;? matches the ;, which is optional
  // 0{0,7} matches any padded zeros, which are optional and go up to 8 chars

  // &#x0040 @ search for the hex values
  $val = preg_replace('/(&#[xX]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val); // with a ;
  // &#00064 @ 0{0,7} matches '0' zero to seven times
  $val = preg_replace('/(&#0{0,8}'.ord($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);

$found = true; // keep replacing as long as the previous round replaced something
while ($found == true) {
  $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); // add in <> to nerf the tag
     $val = preg_replace($pattern, $replacement, $val); // filter out the hex tags
     if ($val_before == $val) {
        // no replacements were made, so exit the loop
        $found = false;
     }
  }
}
return $val;

}

With this input, ip column is empty in mysql. What is wrong in input.
Thanks in advance

Answer 1

How are you reading it back, are you trying this:

echo $_POST['c-ip'];

and make sure that you are using correct super global variable based on the method attribute of your form.

You might want to see though your array to check if IP is coming though from the hidden field:

var_dump ($_POST);

OR

var_dump ($_REQUEST); // not a good idea though

Update

You could simply try this too:

$ip = $_SERVER['REMOTE_ADDR'];
$sql = "INSERT INTO guestbook (id, date, name, email, comment, ip, status) VALUES (' ', NOW(), '$cname', '$cemail', '$ctext' , '$ip', ' ') ";

You see there is no need to save the IP in a hidden field and store it later on, you can get it anytime from PHP’s super global array.