=========================================================================Ubuntu Security Notice USN-4089-1
August 07, 2019

ruby-rack vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Rack could allow cross-site scripting (XSS) attacks.

Software Description:
- ruby-rack: modular Ruby webserver interface

Details:

It was discovered that Rack incorrectly handled carefully crafted requests. A
remote attacker could use this issue to execute a cross-site scripting (XSS)
attack.

Update instructions:

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

Ubuntu 18.04 LTS:
  ruby-rack                       1.6.4-4ubuntu0.1

Ubuntu 16.04 LTS:
  ruby-rack                       1.6.4-3ubuntu0.1

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

References:
  
  CVE-2018-16471

Package Information:
  https://launchpad.net/ubuntu/+source/ruby-rack/1.6.4-4ubuntu0.1
  https://launchpad.net/ubuntu/+source/ruby-rack/1.6.4-3ubuntu0.1