==========================================================================
Ubuntu Security Notice USN-4543-1
September 25, 2020

ruby-sanitize vulnerability
==========================================================================

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

- Ubuntu 20.04 LTS

Summary:

Sanitize could be made to perform XSS attacks if it received specially
crafted input.

Software Description:
- ruby-sanitize: allowlist-based HTML and CSS sanitizer

Details:

Michał Bentkowski discovered that Sanitize did not properly sanitize some
math or svg HTML under certain circumstances. A remote attacker could
potentially exploit this to conduct cross-site scripting (XSS) attacks.
(CVE-2020-4054)

Update instructions:

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

Ubuntu 20.04 LTS:
  ruby-sanitize                   4.6.6-2.1~0.20.04.1

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

References:
  https://usn.ubuntu.com/4543-1
  CVE-2020-4054

Package Information:
  https://launchpad.net/ubuntu/+source/ruby-sanitize/4.6.6-2.1~0.20.04.1