When installing an add-on, Firefox verified the signature before prompting the user; but while the user was confirming the prompt, the underlying add-on file could have been modified and Firefox would not have noticed. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.
989891.791.7Exploitability
AV:NAC:HPR:NUI:RScope
S:UImpact
C:HI:HA:H7.5/CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H