========================================================================== Ubuntu Security Notice USN-4456-1 August 12, 2020 dovecot vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 20.04 LTS - Ubuntu 18.04 LTS - Ubuntu 16.04 LTS Summary: Several security issues were fixed in Dovecot. Software Description: - dovecot: IMAP and POP3 email server Details: It was discovered that Dovecot incorrectly handled deeply nested MIME parts. A remote attacker could possibly use this issue to cause Dovecot to consume resources, resulting in a denial of service. (CVE-2020-12100) It was discovered that Dovecot incorrectly handled memory when using NTLM. A remote attacker could possibly use this issue to cause Dovecot to crash, resulting in a denial of service. (CVE-2020-12673) It was discovered that the Dovecot RPA mechanism incorrectly handled zero-length messages. A remote attacker could possibly use this issue to cause Dovecot to crash, resulting in a denial of service. (CVE-2020-12674) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 20.04 LTS: dovecot-core 1:2.3.7.2-1ubuntu3.2 Ubuntu 18.04 LTS: dovecot-core 1:2.2.33.2-1ubuntu4.6 Ubuntu 16.04 LTS: dovecot-core 1:2.2.22-1ubuntu2.13 In general, a standard system update will make all the necessary changes. References: https://usn.ubuntu.com/4456-1 CVE-2020-12100, CVE-2020-12673, CVE-2020-12674 Package Information: https://launchpad.net/ubuntu/+source/dovecot/1:2.3.7.2-1ubuntu3.2 https://launchpad.net/ubuntu/+source/dovecot/1:2.2.33.2-1ubuntu4.6 https://launchpad.net/ubuntu/+source/dovecot/1:2.2.22-1ubuntu2.13