==========================================================================
Ubuntu Security Notice USN-3515-1
January 04, 2018

ruby1.9.1, ruby2.0, ruby2.3 vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 17.10
- Ubuntu 17.04
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

Ruby could be made to execute arbitrary commands if opened a specially
crafted file.

Software Description:
- ruby2.3: Interpreter of object-oriented scripting language Ruby
- ruby1.9.1: Object-oriented scripting language
- ruby2.0: Object-oriented scripting language

Details:

It was discovered that Ruby allows FTP command injection.
An attacker could use this to cause arbitrary command execution.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 17.10:
  libruby2.3                      2.3.3-1ubuntu1.1
  ruby2.3                         2.3.3-1ubuntu1.1

Ubuntu 17.04:
  libruby2.3                      2.3.3-1ubuntu0.3
  ruby2.3                         2.3.3-1ubuntu0.3

Ubuntu 16.04 LTS:
  libruby2.3                      2.3.1-2~16.04.4
  ruby2.3                         2.3.1-2~16.04.4

Ubuntu 14.04 LTS:
  libruby1.9.1                    1.9.3.484-2ubuntu1.6
  libruby2.0                      2.0.0.484-1ubuntu2.5
  ruby1.9.1                       1.9.3.484-2ubuntu1.6
  ruby1.9.3                       1.9.3.484-2ubuntu1.6
  ruby2.0                         2.0.0.484-1ubuntu2.5

In general, a standard system update will make all the necessary
changes.

References:
  https://www.ubuntu.com/usn/usn-3515-1
  CVE-2017-17405

Package Information:
  https://launchpad.net/ubuntu/+source/ruby2.3/2.3.3-1ubuntu1.1
  https://launchpad.net/ubuntu/+source/ruby2.3/2.3.3-1ubuntu0.3
  https://launchpad.net/ubuntu/+source/ruby2.3/2.3.1-2~16.04.4
  https://launchpad.net/ubuntu/+source/ruby1.9.1/1.9.3.484-2ubuntu1.6
  https://launchpad.net/ubuntu/+source/ruby2.0/2.0.0.484-1ubuntu2.5