CVE-2013-0334 rubygem-bundler: 'bundle install' may install a gem from a source other than expected

Bundler before 1.7, when multiple top-level source lines are used, allows
remote attackers to install arbitrary gems by creating a gem with the same name
as another gem in a different source. A flaw was found in the way Bundler handled
gems available from multiple sources. An attacker with access to one of the sources
could create a malicious gem with the same name, which they could then use to trick
a user into installing, potentially resulting in execution of code from the attacker-supplied
malicious gem.