Jcow 4.2.1 allows remote attackers to obtain sensitive information via a direct request to a .php file, which reveals the installation path in an error message, as demonstrated by themes/default/page.tpl.php and certain other files.

A Code Execution vulnerability exists the attachment parameter to index.php in Jcow CMS 4.x to 4.2 and 5.2 to 5.2.

A Cross-Site Scripting (XSS) vulnerability exists in the g parameter to index.php in Jcow CMS 4.2 and earlier.