Ruby is an interpreted scripting language for quick and easy object-oriented programming. XML-RPC is a remote procedure call protocol encoded in XML.
Nobuhiro IMAI reported that an invalid default value in "utils.rb" causes the security protections of the XML-RPC server to fail.
A remote attacker could exploit this vulnerability to execute arbitrary commands.
There is no known workaround at this time.
All Ruby users should upgrade to the latest available version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-lang/ruby-1.8.2-r2"