Arch Linux: 201902-1 High: Dovecot Authentication Bypass

Arch Linux Security Advisory ASA-201902-1
========================================
Severity: High
Date    : 2019-02-06
CVE-ID  : CVE-2019-3814
Package : dovecot
Type    : authentication bypass
Remote  : Yes
Link    : https://security.archlinux.org/AVG-872

Summary
======
The package dovecot before version 2.3.4.1-1 is vulnerable to
authentication bypass.

Resolution
=========
Upgrade to 2.3.4.1-1.

# pacman -Syu "dovecot>=2.3.4.1-1"

The problem has been fixed upstream in version 2.3.4.1.

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

Description
==========
A vulnerability has been found in Dovecot versions prior to 2.3.4.1,
allowing a remote client in possession of a trusted SSL certificate to
log in as any user, in some configurations.
This affects only installations using auth_ssl_require_client_cert yes and auth_ssl_username_from_cert = yes, and the the attacker might
have access to a trusted certificate without the
ssl_cert_username_field (default to commonName) set in it.

Impact
=====
A remote client in possession of a trusted SSL certificate might be
able to log in as any user.

References
=========
https://dovecot.org/pipermail/dovecot/2019-February/114575.html
https://github.com/dovecot/core/commit/61471a5c42528090cffcca9bceded316746637b7
https://security.archlinux.org/CVE-2019-3814