We have released an updated BitNami JRuby Stack. According to the official JRuby site all users are encouraged to upgrade to this new JRuby version:
"This is a special release of JRuby which only updates our shipped copy of RubyGems to version 1.8.24. This version of RubyGems is the first version to verify that a RubyGems server certficate is valid. This helps to prevent a “man in the middle” style of attack when someone controls a portion of the network between you and the RubyGems server. All users are encouraged to upgrade to JRuby 1.6.7.2."
Apart from JRuby, this stack also includes updated Tomcat and Java versions.
If you haven't started with JRuby yet and you want to give it a try, take a look at our Quick Start Guide.
Enjoy!