Arch Linux Security Advisory ASA-201804-8
========================================
Severity: High
Date    : 2018-04-19
CVE-ID  : CVE-2018-9846
Package : roundcubemail
Type    : arbitrary command execution
Remote  : Yes
Link    : https://security.archlinux.org/AVG-670

Summary
======
The package roundcubemail before version 1.3.6-1 is vulnerable to
arbitrary command execution.

Resolution
=========
Upgrade to 1.3.6-1.

# pacman -Syu "roundcubemail>=1.3.6-1"

The problem has been fixed upstream in version 1.3.6.

Workaround
=========
Disable the archive plugin.

Description
==========
In Roundcube from versions 1.2.0 to 1.3.5, with the archive plugin
enabled and configured, it's possible to exploit the unsanitized, user-
controlled "_uid" parameter (in an archive.php
_task=mail&_mbox=INBOX&_action=plugin.move2archive request) to perform
an MX (IMAP) injection attack by placing an IMAP command after a %0d%0a
sequence. NOTE: this is less easily exploitable in 1.3.4 and later
because of a Same Origin Policy protection mechanism.

Impact
=====
A remote attacker is able to execute arbitrary IMAP commands via a
specially crafted url.

References
=========
https://github.com/roundcube/roundcubemail/issues/6229
https://github.com/roundcube/roundcubemail/issues/6238
https://medium.com/@ndrbasi/cve-2018-9846-roundcube-303097048b0a
https://roundcube.net/news/2018/04/11/security-update-1.3.6
https://security.archlinux.org/CVE-2018-9846