rubygem-actionpack: arbitrary HTML or webscript execution

1) A cross-site scripting (XSS) flaw was found in the way the String class, used in Ruby on Rails, performed HTML escaping of SafeBuffer objects, when such objects were manipulated directly via '[]' method or other methods, also returning new instances of SafeBuffer object. By using these methods, such newly returned SafeBuffer instances would be inadvertently marked as HTML safe. If a Ruby on Rails application used SafeBuffer objects this way, a remote attacker could provide a specially-crafted input, which once processed by such SafeBuffer instance would pass the HTML escaping test without further filtering, possibly leading to arbitrary HTML or webscript execution.

2) A cross-site scripting (XSS) flaw was found in the way 'select' helper method of the Ruby on Rails performed HTML escaping of 'select' HTML tag options, when the tags were created manually. In this case, the select tag values might end up unescaped. A remote-attacker could provide a specially-crafted input to Ruby on Rails application, using select tags this way, which potentially resulted into arbitrary HTML or webscript execution.