Thunderbird unprotects a secret OpenPGP key prior to using it for a decryption, signing or key import task. If the task runs into a failure, the secret key may remain in memory in its unprotected state. This vulnerability affects Thunderbird < 78.8.1.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-29950
• https://bugzilla.mozilla.org/show_bug.cgi?id=1673239
• https://www.mozilla.org/security/advisories/mfsa2021-17/