Cross-site scripting (XSS) vulnerability in spell-check-savedicts.php in the htmlarea SpellChecker module, as used in Serendipity before 1.7.3 and possibly other products, allows remote attackers to inject arbitrary web script or HTML via the to_r_list parameter.
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.