Language: PHP
Label: vulnerable
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:
function form_file($name, $label)
{
    return form_element(
        $label,
        sprintf('<input id="form_%1$s" type="file" name="%1$s" />', $name),
        'form_' . $name
    );
}