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 setup($config)
    {
        $a = $this->addBlankElement('a');
        $a->attr_transform_post[] = new HTMLPurifier_AttrTransform_Nofollow();
    }