Title:Remote command injection and SQLi in Ruby Gem brbackup-0.1.1
The following code exposes the database password to the command line, if this gem is used in the context of a rails application command injection can be achived by placing shell metacharacters like ; in the user supplied input for variable dbuser. I suspect the other variables are injectable by playing with " and '.

Also line 313 is vulnerable to SQL injection via the '#{name}' variable.

From: brbackup-0.1.1/lib/brbackup.rb

311-
312-    def db_has_myisam?(name)
313-      query = "SELECT 1 FROM information_schema.tables WHERE table_schema='#{name}' AND engine='MyISAM' LIMIT 1;"
314:      %x{mysql -u #{dbuser} {password_option} -N -e"{query}"}.strip == '1'
315-    end
316-
317-    def restore_database(name, io)

Where password_option will expose the password to the process table if the password is not nil or empty.

338-  def password_option
339     dbpass.nil? || dbpass.empty? ? "" : "-p'#{dbpass}'"