Remote command execution in Ruby Gem ldoce 0.0.2

Remote command execution in Ruby Gem ldoce 0.0.2

Larry W. Cashdollar
@_larry0
3/25/2013

Ldoce Ruby Gem:

Easily interface with the Longman Dictionary of Contemporary English API from Ruby:

NB currently mac only as it depends on the afplay command.
https://rubygems.org/gems/ldoce

https://github.com/markburns/ldoce

Ldoce passes an mp3 url to commandline for audio output of the pronunciation of a dictonary word:

If the URL or filename for the mp3 files contain shell metacharacters code can be executed remotely as the client:

[./ldoce-0.0.2/lib/ldoce/word.rb]

  if mp3?
    unless File.exists? filename
      command = "curl #{mp3_url} -silent > {filename}"
      `{command}`
    end
    `afplay #{filename}`
  end

This vulnerability has been assigned CVE-ID CVE-2013-1911

http://otiose.dhs.org/advisories/ldoce-0.0.2-cmd-exec.html