The Hostel plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'wphostel-book' shortcode in all versions up to and including 1.1.7. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, the second shortcode attribute (used as button text) is passed to the `$text` variable without sanitization at line 79 and then output directly into an HTML `value` attribute at line 91 without `esc_attr()` or any other escaping. 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.
https://plugins.trac.wordpress.org/changeset?reponame=&old=3480942%40hostel&new=3480942%40hostel
https://plugins.trac.wordpress.org/browser/hostel/trunk/models/hostel.php#L195
https://plugins.trac.wordpress.org/browser/hostel/trunk/controllers/shortcodes.php#L91
https://plugins.trac.wordpress.org/browser/hostel/trunk/controllers/shortcodes.php#L79
https://plugins.trac.wordpress.org/browser/hostel/tags/1.1.6/models/hostel.php#L195
https://plugins.trac.wordpress.org/browser/hostel/tags/1.1.6/controllers/shortcodes.php#L91
https://plugins.trac.wordpress.org/browser/hostel/tags/1.1.6/controllers/shortcodes.php#L79