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 validate($string, $config, $context)
    {
        $string = $this->parseCDATA($string);

        // Optimizations
        if ($string === '') {
            return false;
        }
        if ($string === '0') {
            return '0';
        }
        if (strlen($string) === 1) {
            return false;
        }

        $length = HTMLPurifier_Length::make($string);
        if (!$length->isValid()) {
            return false;
        }

        if ($this->min) {
            $c = $length->compareTo($this->min);
            if ($c === false) {
                return false;
            }
            if ($c < 0) {
                return false;
            }
        }
        if ($this->max) {
            $c = $length->compareTo($this->max);
            if ($c === false) {
                return false;
            }
            if ($c > 0) {
                return false;
            }
        }
        return $length->toString();
    }