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:
    protected function doSetupProprietary($config)
    {
        // Internet Explorer only scrollbar colors
        $this->info['scrollbar-arrow-color'] = new HTMLPurifier_AttrDef_CSS_Color();
        $this->info['scrollbar-base-color'] = new HTMLPurifier_AttrDef_CSS_Color();
        $this->info['scrollbar-darkshadow-color'] = new HTMLPurifier_AttrDef_CSS_Color();
        $this->info['scrollbar-face-color'] = new HTMLPurifier_AttrDef_CSS_Color();
        $this->info['scrollbar-highlight-color'] = new HTMLPurifier_AttrDef_CSS_Color();
        $this->info['scrollbar-shadow-color'] = new HTMLPurifier_AttrDef_CSS_Color();

        // vendor specific prefixes of opacity
        $this->info['-moz-opacity'] = new HTMLPurifier_AttrDef_CSS_AlphaValue();
        $this->info['-khtml-opacity'] = new HTMLPurifier_AttrDef_CSS_AlphaValue();

        // only opacity, for now
        $this->info['filter'] = new HTMLPurifier_AttrDef_CSS_Filter();

        // more CSS3
        $this->info['page-break-after'] =
        $this->info['page-break-before'] = new HTMLPurifier_AttrDef_Enum(
            array(
                'auto',
                'always',
                'avoid',
                'left',
                'right'
            )
        );
        $this->info['page-break-inside'] = new HTMLPurifier_AttrDef_Enum(array('auto', 'avoid'));

        $border_radius = new HTMLPurifier_AttrDef_CSS_Composite(
            array(
                new HTMLPurifier_AttrDef_CSS_Percentage(true), // disallow negative
                new HTMLPurifier_AttrDef_CSS_Length('0') // disallow negative
            ));

        $this->info['border-top-left-radius'] =
        $this->info['border-top-right-radius'] =
        $this->info['border-bottom-right-radius'] =
        $this->info['border-bottom-left-radius'] = new HTMLPurifier_AttrDef_CSS_Multiple($border_radius, 2);
        // TODO: support SLASH syntax
        $this->info['border-radius'] = new HTMLPurifier_AttrDef_CSS_Multiple($border_radius, 4);

    }