A WebKitGTK security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, and 20.10 to address a large number of security issues.

==========================================================================
Ubuntu Security Notice USN-4739-1
February 18, 2021

webkit2gtk vulnerability
==========================================================================

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

- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in WebKitGTK.

Software Description:
- webkit2gtk: Web content engine library for GTK+

Details:

A large number of security issues were discovered in the WebKitGTK Web and
JavaScript engines. If a user were tricked into viewing a malicious
website, a remote attacker could exploit a variety of issues related to web
browser security, including cross-site scripting attacks, denial of service
attacks, and arbitrary code execution.

Update instructions:

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

Ubuntu 20.10:
libjavascriptcoregtk-4.0-18 2.30.5-0ubuntu0.20.10.1
libwebkit2gtk-4.0-37 2.30.5-0ubuntu0.20.10.1

Ubuntu 20.04 LTS:
libjavascriptcoregtk-4.0-18 2.30.5-0ubuntu0.20.04.1
libwebkit2gtk-4.0-37 2.30.5-0ubuntu0.20.04.1

Ubuntu 18.04 LTS:
libjavascriptcoregtk-4.0-18 2.30.5-0ubuntu0.18.04.1
libwebkit2gtk-4.0-37 2.30.5-0ubuntu0.18.04.1

This update uses a new upstream release, which includes additional bug
fixes. After a standard system update you need to restart any applications
that use WebKitGTK, such as Epiphany, to make all the necessary changes.

References:
  https://usn.ubuntu.com/4739-1
CVE-2020-13558

Package Information:
  https://launchpad.net/ubuntu/+source/webkit2gtk/2.30.5-0ubuntu0.20.10.1
  https://launchpad.net/ubuntu/+source/webkit2gtk/2.30.5-0ubuntu0.20.04.1
  https://launchpad.net/ubuntu/+source/webkit2gtk/2.30.5-0ubuntu0.18.04.1