The Motors – Car Dealership & Classified Listings Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'stm_f_s[make]' parameter in all versions up to, and including, 1.4.128 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the Free Listing Submission feature to be enabled, which is shipped on by default via the Setup Wizard demo configuration.