Ubuntu 20.10 USN-4674-1 Moderate: Dovecot DoS and Access Issues

ubuntu

January 4, 2021

Several security issues were fixed in Dovecot.

Summary

Several security issues were fixed in Dovecot.

Software Description:

- dovecot: IMAP and POP3 email server

Details:

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. (CVE-2020-24386)

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. (CVE-2020-25275)

Topics Covered

security advisory DoS attack moderate severity email server Dovecot issue

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.10:
  dovecot-core                    1:2.3.11.3+dfsg1-2ubuntu0.1

Ubuntu 20.04 LTS:
  dovecot-core                    1:2.3.7.2-1ubuntu3.3

Ubuntu 18.04 LTS:
  dovecot-core                    1:2.2.33.2-1ubuntu4.7

Ubuntu 16.04 LTS:
  dovecot-core                    1:2.2.22-1ubuntu2.14

In general, a standard system update will make all the necessary changes.