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 getChildDef($def)
    {
        if ($def->content_model_type != 'strictblockquote') {
            return parent::getChildDef($def);
        }
        return new HTMLPurifier_ChildDef_StrictBlockquote($def->content_model);
    }