rack/file.rb (Rack::File) in Rack 1.5.x before 1.5.2 and 1.4.x before 1.4.5 allows attackers to access arbitrary files outside the intended root directory via a crafted PATH_INFO environment variable, probably a directory traversal vulnerability that is remotely exploitable, aka "symlink path traversals."

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.

Unspecified vulnerability in CrawlTrack before 3.2.7, when a public stats page is provided, allows remote attackers to execute arbitrary PHP code via unknown vectors.