ning-mengcn/taint

Taint is a PHP extension, used for detecting XSS codes

Taint

php extension used to detect XSS codes(tainted string), And also can be used to spot sql injection vulnerabilities, shell inject, etc.

The idea is from https://wiki.php.net/rfc/taint, I implemented it in a php extension which make the patch no-needed.

Please note that do not enable this extension in product env, since it will slowdown your app.

Requirement

• PHP-5.2 +

##Note Due to complication of PHP8.0 implementation, taint is not going to be compatible with PHP8.0+.

Install

taint is an PECL extension, thus you can simply install it by:

pecl install taint

Compile taint in Linux

$/path/to/phpize
$./configure --with-php-config=/path/to/php-config/
$make && make install

Usage

When taint is enabled, if you pass a tainted string(comes from $_GET, $_POST or $_COOKIE) to some functions, taint will warn you about that.

<?php
$a = trim($_GET['a']);

$file_name = '/tmp' .  $a;
$output    = "Welcome, {$a} !!!";
$var       = "output";
$sql       = "Select *  from " . $a;
$sql      .= "ooxx";

echo $output;

print $$var;

include($file_name);

mysql_query($sql);

The above example will output something similar to:

Warning: main() [function.echo]: Attempt to echo a string that might be tainted

Warning: main() [function.echo]: Attempt to print a string that might be tainted

Warning: include() [function.include]: File path contains data that might be tainted

Warning: mysql_query() [function.mysql-query]: SQL statement contains data that might be tainted

If you need to hide the errors for a particular script, you can:

ini_set('taint.error_level', 0);