Ruby on Rails 2.1.x, 2.2.x, and 2.3.x before 2.3.11, and 3.x before 3.0.4, does not properly validate HTTP requests that contain an X-Requested-With header, which makes it easier for remote attackers to conduct cross-site request forgery (CSRF) attacks via forged (1) AJAX or (2) API requests that leverage "combinations of browser plugins and HTTP redirects," a related issue to CVE-2011-0696.