How realistic is it that this vulnerability can be exploited for $BAD_THINGS? https://www.mozilla.org/en-US/security/advisories/mfsa2021-51/ https://www.mozill

How realistic is it that this vulnerability can be exploited for $BAD_THINGS? https://www.mozilla.org/en-US/security/advisories/mfsa2021-51/ https://www.mozilla.org/en-US/security/advisories/mfsa2021-5... notes "This vulnerability does NOT impact Mozilla Firefox. However, email clients and PDF viewers that use NSS for signature verification, such as Thunderbird, LibreOffice, Evolution and Evince are believed to be impacted.".