Mozilla developers and community members reported memory safety bugs present in Firefox 69 and Firefox ESR 68.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-11764
• https://bugzilla.mozilla.org/buglist.cgi?bug_id=1558522%2C1577061%2C1548044%2C1571223%2C1573048%2C1578933%2C1575217%2C1583684%2C1586845%2C1581950%2C1583463%2C1586599
• https://security.gentoo.org/glsa/202003-10
• https://usn.ubuntu.com/4335-1/
• https://www.mozilla.org/security/advisories/mfsa2019-33/
• https://www.mozilla.org/security/advisories/mfsa2019-34/
• https://www.mozilla.org/security/advisories/mfsa2019-35/