Upgrade Ruby Version

Hi there,

You are receiving this email because you’re running at least one Ruby
(MRI) application on Heroku.

Last Friday, there was a security vulnerability announced with the
libyaml library used in the Psych gem. This could lead to arbitrary code
execution when parsing YAML.  To ensure you are running on the patched
version of ruby, please follow the steps below.

Check if you’re affected
Run the following on your app:

$ heroku run “ruby -rpsych -e \”p Psych.libyaml_version.join(‘.’)\”” -a
<app name>

If you see the following error message, then you are not vulnerable and
can ignore the rest of this email:
<internal:lib/rubygems/custom_require>:29:in `require': no such file to
load -- psych (LoadError)
from <internal:lib/rubygems/custom_require>:29:in `require'

If you are using Psych, the command will return a version number.  If
the version returned is less than 0.1.6 you are vulnerable. Please
follow the instructions below.

If you do not explicitly use the Psych Gem
If you don’t explicitly use the Psych gem and you’re on Ruby 1.9.2+,
you’ll need to push a new commit to your app, which will cause a deploy
and update your version of ruby automatically. If you don’t want to push
any actual changes, this commit can be empty:

$ git commit --allow-empty -m “upgrade ruby version”

$ git push heroku master