A fixed-size stack buffer could overflow in nrappkit when doing WebRTC signaling. This resulted in a potentially exploitable crash in some instances. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.
https://bugzilla.mozilla.org/show_bug.cgi?id=1577719
https://security.gentoo.org/glsa/202003-10
https://usn.ubuntu.com/4335-1/
https://www.mozilla.org/security/advisories/mfsa2019-33/