A firefox-esr security update has been released for Debian GNU/Linux 9 LTS to address multiple security issues.

DLA 2633-1: firefox-esr security update

- -----------------------------------------------------------------------
Debian LTS Advisory DLA-2633-1 debian-lts@lists.debian.org
  https://www.debian.org/lts/security/ Utkarsh Gupta
April 23, 2021   https://wiki.debian.org/LTS
- -----------------------------------------------------------------------

Package : firefox-esr
Version : 78.10.0esr-1~deb9u1
CVE ID : CVE-2021-23961 CVE-2021-23994 CVE-2021-23995
CVE-2021-23998 CVE-2021-23999 CVE-2021-24002
CVE-2021-29945 CVE-2021-29946

Multiple security issues have been found in the Mozilla Firefox web
browser, which could potentially result in the execution of arbitrary
code, information disclosure, privilege escalation or spoofing.

For Debian 9 stretch, these problems have been fixed in version
78.10.0esr-1~deb9u1.

We recommend that you upgrade your firefox-esr packages.

For the detailed security status of firefox-esr please refer to
its security tracker page at:
  https://security-tracker.debian.org/tracker/firefox-esr

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at:   https://wiki.debian.org/LTS