=========================================================================Ubuntu Security Notice USN-3808-1
November 05, 2018

ruby1.9.1, ruby2.0, ruby2.3, ruby2.5 vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in Ruby.

Software Description:
- ruby2.5: Interpreter of object-oriented scripting language Ruby
- ruby2.3: Object-oriented scripting language
- ruby1.9.1: Object-oriented scripting language
- ruby2.0: Object-oriented scripting language

Details:

It was discovered that Ruby incorrectly handled certain X.509
certificates. An attacker could possibly use this issue to
bypass the certificate check. (CVE-2018-16395)

It was discovered that Ruby incorrectly handled certain
inputs. An attacker could possibly use this issue to execute
arbitrary code. (CVE-2018-16396)

Update instructions:

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

Ubuntu 18.10:
  libruby2.5                      2.5.1-5ubuntu4.1
  ruby2.5                         2.5.1-5ubuntu4.1

Ubuntu 18.04 LTS:
  libruby2.5                      2.5.1-1ubuntu1.1
  ruby2.5                         2.5.1-1ubuntu1.1

Ubuntu 16.04 LTS:
  libruby2.3                      2.3.1-2~16.04.11
  ruby2.3                         2.3.1-2~16.04.11

Ubuntu 14.04 LTS:
  libruby1.9.1                    1.9.3.484-2ubuntu1.13
  libruby2.0                      2.0.0.484-1ubuntu2.11
  ruby1.9.1                       1.9.3.484-2ubuntu1.13
  ruby1.9.3                       1.9.3.484-2ubuntu1.13
  ruby2.0                         2.0.0.484-1ubuntu2.11

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

References:
  https://ubuntu.com/security/notices/USN-3808-1
  CVE-2018-16395, CVE-2018-16396

Package Information:
  https://launchpad.net/ubuntu/+source/ruby2.5/2.5.1-5ubuntu4.1
  https://launchpad.net/ubuntu/+source/ruby2.5/2.5.1-1ubuntu1.1
  https://launchpad.net/ubuntu/+source/ruby2.3/2.3.1-2~16.04.11
  https://launchpad.net/ubuntu/+source/ruby1.9.1/1.9.3.484-2ubuntu1.13
  https://launchpad.net/ubuntu/+source/ruby2.0/2.0.0.484-1ubuntu2.11