CVE-2016-2098.yml

---
gem: actionpack
framework: rails
cve: 2016-2098
ghsa: 78rc-8c29-p45g
url: https://groups.google.com/forum/#!topic/rubyonrails-security/ly-IH-fxr_Q
title: Possible remote code execution vulnerability in Action Pack
date: 2016-02-29
description: |
  There is a possible remote code execution vulnerability in Action Pack.
  This vulnerability has been assigned the CVE identifier CVE-2016-2098.

  Versions Affected:  3.2.x, 4.0.x, 4.1.x, 4.2.x
  Not affected:       5.0+
  Fixed Versions:     3.2.22.2, 4.1.14.2, 4.2.5.2

  Impact
  ------
  Applications that pass unverified user input to the `render` method in a
  controller or a view may be vulnerable to a code injection.

  Impacted code will look like this:

  ```ruby
  class TestController < ApplicationController
    def show
      render params[:id]
    end
  end
  ```

  An attacker could use the request parameters to coerce the above example
  to execute arbitrary ruby code.

  All users running an affected release should either upgrade or use one of
  the workarounds immediately.

  Releases
  --------
  The FIXED releases are available at the normal locations.

  Workarounds
  -----------
  A workaround to this issue is to not pass arbitrary user input to the `render`
  method. Instead, verify that data before passing it to the `render` method.

  For example, change this:

  ```ruby
  def index
    render params[:id]
  end
  ```

  To this:

  ```ruby
  def index
    render verify_template(params[:id])
  end

  private
  def verify_template(name)
    # add verification logic particular to your application here
  end
  ```

  Patches
  -------
  To aid users who aren't able to upgrade immediately we have provided a
  patch for it. It is in git-am format and consist of a single changeset.

  * 3-2-secure_inline_with_params.patch - Patch for 3.2 series
  * 4-1-secure_inline_with_params.patch - Patch for 4.1 series
  * 4-2-secure_inline_with_params.patch - Patch for 4.2 series

  Credits
  -------
  Thanks to both Tobias Kraze from makandra and joernchen of Phenoelit for
  reporting this!
cvss_v3: 7.3
unaffected_versions:
  - ">= 5.0.0.beta1"
patched_versions:
  - "~> 3.2.22.2"
  - "~> 4.2.5, >= 4.2.5.2"
  - "~> 4.1.14, >= 4.1.14.2"