Multiple security issues have been found in the Mozilla Firefox web browser, which could potentially result in the execution of arbitrary code, information disclosure, phishing, cross-site scripting or a DNS rebinding attack.
For the stable distribution (buster), these problems have been fixed in version 78.5.0esr-1~deb10u1.
We recommend that you upgrade your firefox-esr packages.
Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/