Cross-site scripting (XSS) vulnerability in lib/rack/ssl.rb in the rack-ssl gem before 1.4.0 for Ruby allows remote attackers to inject arbitrary web script or HTML via a URI, which might not be properly handled by third-party adapters such as JRuby-Rack.

lib/rack/multipart.rb in Rack before 1.1.4, 1.2.x before 1.2.6, 1.3.x before 1.3.7, and 1.4.x before 1.4.2 uses an incorrect regular expression, which allows remote attackers to cause a denial of service (infinite loop) via a crafted Content-Disposion header.

Unspecified vulnerability in Rack::Auth::AbstractRequest in Rack 1.1.x before 1.1.5, 1.2.x before 1.2.7, 1.3.x before 1.3.9, and 1.4.x before 1.4.4 allows remote attackers to cause a denial of service via unknown vectors related to "symbolized arbitrary strings."

multipart/parser.rb in Rack 1.3.x before 1.3.8 and 1.4.x before 1.4.3 allows remote attackers to cause a denial of service (memory consumption and out-of-memory error) via a long string in a Multipart HTTP packet.

Rack::Session::Cookie in Rack 1.5.x before 1.5.2, 1.4.x before 1.4.5, 1.3.x before 1.3.10, 1.2.x before 1.2.8, and 1.1.x before 1.1.6 allows remote attackers to guess the session cookie, gain privileges, and execute arbitrary code via a timing attack involving an HMAC comparison function that does not run in constant time.

Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.