sprockets vulnerable to Path Traversal

Multiple directory traversal vulnerabilities in server.rb in Sprockets before 2.0.5, 2.1.x before 2.1.4, 2.2.x before 2.2.3, 2.3.x before 2.3.3, 2.4.x before 2.4.6, 2.5.x before 2.5.1, 2.6.x and 2.7.x before 2.7.1, 2.8.x before 2.8.3, 2.9.x before 2.9.4, 2.10.x before 2.10.2, 2.11.x before 2.11.3, 2.12.x before 2.12.3, and 3.x before 3.0.0.beta.3, as distributed with Ruby on Rails 3.x and 4.x, allow remote attackers to determine the existence of files outside the application root via a ../ (dot dot slash) sequence with (1) double slashes or (2) URL encoding.