Ubuntu Security Notice USN-4674-1

Ubuntu Security Notice 4674-1 - It was discovered that Dovecot incorrectly handled certain imap hibernation commands. A remote authenticated attacker could possibly use this issue to access other users' email. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, and Ubuntu 20.10. Innokentii Sennovskiy discovered that Dovecot incorrectly handled MIME parsing. A remote attacker could possibly use this issue to cause Dovecot to crash, resulting in a denial of service. Various other issues were also addressed.