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.
Ruby on Rails 2.3.9 and 3.0.0 does not properly handle nested attributes, which allows remote attackers to modify arbitrary records by changing the names of parameters for form inputs.
The session fixation protection mechanism in cgi_process.rb in Rails 1.2.4, as used in Ruby on Rails, removes the :cookie_only attribute from the DEFAULT_SESSION_OPTIONS constant, which effectively causes cookie_only to be applied only to the first instantiation of CgiRequest, which allows remote attackers to conduct session fixation attacks. NOTE: this is due to an incomplete fix for CVE-2007-5380.