MGASA-2020-0252

Updated ruby-rack packages fix security vulnerabilities:

There's a possible information leak / session hijack vulnerability in Rack(RubyGem rack). Attackers may be able to find and hijack sessions by using timing attacks targeting the session id. Session ids are usually stored and indexed in a database that uses some kind of scheme for speeding up lookups of that session id. By carefully measuring the amount of time it takes to look up a session, an attacker may be able to find a valid session id and hijack the session. The session id itself may be generated randomly, but the way the session is indexed by the backing store does not use a secure comparison (CVE-2019-16782).

If certain directories exist in a director that is managed by Rack::Directory, an attacker could, using this vulnerability, read the contents of files on the server that were outside of the root specified in the Rack::Directory initializer (CVE-2020-8161).