Language: PHP
Label: safe
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
    public function escape($string, $quote = null)
    {
        // Workaround for APC bug on Mac Leopard reported by sidepodcast
        // http://htmlpurifier.org/phorum/read.php?3,4823,4846
        if ($quote === null) {
            $quote = ENT_COMPAT;
        }
        return htmlspecialchars($string, $quote, 'UTF-8');
    }