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://www.mozilla.org/security/advisories/mfsa2019-35/
https://www.mozilla.org/security/advisories/mfsa2019-34/
https://www.mozilla.org/security/advisories/mfsa2019-33/
https://usn.ubuntu.com/4335-1/