The sanitize helper in lib/action_controller/vendor/html-scanner/html/sanitizer.rb in the Action Pack component in Ruby on Rails before 2.3.18, 3.0.x and 3.1.x before 3.1.12, and 3.2.x before 3.2.13 does not properly handle encoded : (colon) characters in URLs, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted scheme name, as demonstrated by including a : sequence.
ActiveRecord in Ruby on Rails before 2.3.17, 3.1.x before 3.1.11, and 3.2.x before 3.2.12 allows remote attackers to bypass the attr_protected protection mechanism and modify protected model attributes via a crafted request.
SQL injection vulnerability in the Active Record component in Ruby on Rails before 3.0.18, 3.1.x before 3.1.9, and 3.2.x before 3.2.10 allows remote attackers to execute arbitrary SQL commands via a crafted request that leverages incorrect behavior of dynamic finders in applications that can use unexpected data types in certain find_by_ method calls.
The Authlogic gem for Ruby on Rails, when used with certain versions before 3.2.10, makes potentially unsafe find_by_id method calls, which might allow remote attackers to conduct CVE-2012-6496 SQL injection attacks via a crafted parameter in environments that have a known secret_token value, as demonstrated by a value contained in secret_token.rb in an open-source product.