Subject: [ASA-202004-6] firefox: arbitrary code execution

Arch Linux Security Advisory ASA-202004-6
=========================================

Severity: Critical
Date    : 2020-04-04
CVE-ID  : CVE-2020-6819 CVE-2020-6820
Package : firefox
Type    : arbitrary code execution
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1125

Summary
=======

The package firefox before version 74.0.1-1 is vulnerable to arbitrary
code execution.

Resolution
==========

Upgrade to 74.0.1-1.

# pacman -Syu "firefox>=74.0.1-1"

The problems have been fixed upstream in version 74.0.1.

Workaround
==========

None.

Description
===========

- CVE-2020-6819 (arbitrary code execution)

A use-after-free vulnerability has been found in Firefox before 74.0.1
and Thunderbird before 68.7.0 where under certain conditions, when
running the nsDocShell destructor, a race condition can cause a use-
after-free. Mozilla is aware of targeted attacks in the wild abusing
this flaw.

- CVE-2020-6820 (arbitrary code execution)

A use-after-free vulnerability has been found in Firefox before 74.0.1
and Thunderbird before 68.7.0 where, under certain conditions, when
handling a ReadableStream, a race condition can cause a use-after-free.
Mozilla is aware of targeted attacks in the wild abusing this flaw.

Impact
======

A remote attacker can execute arbitrary code on the affected host.

References
==========

https://www.mozilla.org/en-US/security/advisories/mfsa2020-11/
https://www.mozilla.org/en-US/security/advisories/mfsa2020-11/#CVE-2020-6819
https://bugzilla.mozilla.org/show_bug.cgi?id=1620818
https://www.mozilla.org/en-US/security/advisories/mfsa2020-11/#CVE-2020-6820
https://bugzilla.mozilla.org/show_bug.cgi?id=1626728
https://security.archlinux.org/CVE-2020-6819
https://security.archlinux.org/CVE-2020-6820