Arch Linux Security Advisory ASA-201905-6
========================================
Severity: Medium
Date    : 2019-05-06
CVE-ID  : CVE-2019-11494 CVE-2019-11499
Package : dovecot
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-954

Summary
======
The package dovecot before version 2.3.6-1 is vulnerable to denial of
service.

Resolution
=========
Upgrade to 2.3.6-1.

# pacman -Syu "dovecot>=2.3.6-1"

The problems have been fixed upstream in version 2.3.6.

Workaround
=========
None.

Description
==========
- CVE-2019-11494 (denial of service)

Submission-login crashes with signal 11 due to null pointer access when
authentication is aborted by disconnecting. This can lead to denial-of
service attack by persistent attacker(s).

- CVE-2019-11499 (denial of service)

Submission-login crashes when authentication is started over TLS
secured channel and invalid authentication message is sent. This can
lead to denial-of-service attack by persistent attacker(s).

Impact
=====
A remote attacker is able to cause a denial of service by sending
invalid authentication messages or aborting the authentication process.

References
=========
https://dovecot.org/doc/NEWS-2.3
https://www.mail-archive.com/fulldisclosure@seclists.org/msg06126.html
https://dovecot.org/pipermail/dovecot/2019-April/115757.html
https://dovecot.org/pipermail/dovecot/2019-April/115758.html
https://security.archlinux.org/CVE-2019-11494
https://security.archlinux.org/CVE-2019-11499