The FileStore capability in CGI::Session for Ruby before 1.8.1, and possibly PStore, creates files with insecure permissions, which can allow local users to steal session information and hijack sessions.

The CGI module in Ruby 1.6 before 1.6.8, and 1.8 before 1.8.2, allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a certain HTTP request.

The XMLRPC server in utils.rb for the ruby library (libruby) 1.8 sets an invalid default value that prevents "security protection" using handlers, which allows remote attackers to execute arbitrary commands.

Ruby 1.6.x up to 1.6.8, 1.8.x up to 1.8.2, and 1.9.0 development up to 2005-09-01 allows attackers to bypass safe level and taint flag protections and execute disallowed code when Ruby processes a program through standard input (stdin).

The HTTP/XMLRPC server in Ruby before 1.8.2 uses blocking sockets, which allows attackers to cause a denial of service (blocked connections) via a large amount of data.

Multiple unspecified vulnerabilities in Ruby before 1.8.5 allow remote attackers to bypass "safe level" checks via unspecified vectors involving (1) the alias function and (2) "directory operations".