The a few days ago published Firefox version 69 contains numerous innovations in addition to a number of important vulnerability fixes. The same applies to the new versions 60.9 and 68.1 of the ESR (Extended Support Relase) version of the browser – and to the (still) ESR 60.x based Tor Browser. The latter is now available in version 8.5.5. As Mozilla’s security advisories on Firefox 69 and ESR 68.1 show, both versions include a vulnerable-but Windows-specific-vulnerability. To exploit CVE-2019-11751, an attacker would have to make his victim run Firefox out of the context of another program, such as by clicking a link in a chat. If this succeeds, it could save logfiles anywhere, thanks to inadequate checks of command line parameters. For example, in the startup folder of the operating system to bring malicious code to run the next time the system is booted. The critical vulnerability is joined by nine (ESR 68.1) or 11 (Firefox 69) vulnerabilities with “high” – and some with “medium” rating.
The security advisory for ESR 60.9 contains seven “highs” – weak points, which were therefore also closed in the Tor Browser. Among other things, attackers could have used them to run the Mozilla maintenance service with extended rights or provoke potentially exploitable browser crashes. The developers of Tor Browser have made additional bugfixes in addition to updating the underlying ESR version.