Red Hat Security Advisory 2013-1441-01 – RubyGems is the Ruby standard for publishing and managing third-party libraries. It was found that RubyGems did not verify SSL connections. This could lead to man-in-the-middle attacks. It was found that, when using RubyGems, the connection could be redirected from HTTPS to HTTP. This could lead to a user believing they are installing a gem via HTTPS, when the connection may have been silently downgraded to HTTP…. Red Hat Security Advisory 2013-1441-01 – RubyGems is the Ruby standard for publishing and managing third-party libraries. It was found that RubyGems did not verify SSL connections. This could lead to man-in-the-middle attacks. It was found that, when using RubyGems, the connection could be redirected from HTTPS to HTTP. This could lead to a user believing they are installing a gem via HTTPS, when the connection may have been silently downgraded to HTTP.

Read more http://packetstormsecurity.com/files/123646/RHSA-2013-1441-01.txt