The self.run_gpg function in lib/rgpg/gpg_helper.rb in the rgpg gem before 0.2.3 for Ruby allows remote attackers to execute arbitrary commands via shell metacharacters in unspecified vectors.
Improper Control of Generation of Code The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.