USN-5058-1: Thunderbird vulnerabilities

It was discovered that Thunderbird didn't ignore IMAP server responses prior to completion of the STARTTLS handshake. A person-in-the-middle could potentially exploit this to trick Thunderbird into showing incorrect information. (CVE-2021-29969) Multiple security issues were discovered in Thunderbird. If a user were tricked into opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service, or execute arbitrary code. (CVE-2021-29970, CVE-2021-29976, CVE-2021-29980, CVE-2021-29984, CVE-2021-29985, CVE-2021-29986, CVE-2021-29988, CVE-2021-29989, CVE-2021-30547)