The Events In City plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'org-events' shortcode in versions up to, and including, 3.0. This is due to insufficient input sanitization and output escaping on user supplied attributes (such as 'organizer_id', 'width', 'height', 'transparency', 'header', 'border', and 'layout') in the org_event_scode() function. The attribute values are concatenated directly into HTML attributes without esc_attr(). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.