Deterministic Register Confusion Vulnerability in Firefox and Thunderbird Versions < 91

CVE-2021-29981 · HIGH Severity

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

An issue present in lowering/register allocation could have led to obscure but deterministic register confusion failures in JITted code that would lead to a potentially exploitable crash. This vulnerability affects Firefox < 91 and Thunderbird < 91.

Learn more about our Web Application Penetration Testing UK.