Arch Linux Security Advisory ASA-202002-6
========================================
Severity: Medium
Date    : 2020-02-12
CVE-ID  : CVE-2020-7046 CVE-2020-7957
Package : dovecot
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1097

Summary
======
The package dovecot before version 2.3.9.3-1 is vulnerable to denial of
service.

Resolution
=========
Upgrade to 2.3.9.3-1.

# pacman -Syu "dovecot>=2.3.9.3-1"

The problems have been fixed upstream in version 2.3.9.3.

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

Description
==========
- CVE-2020-7046 (denial of service)

A denial of service has been found in Dovecot before 2.3.9.3, where
lib-smtp doesn't handle truncated command parameters properly,
resulting in infinite loop taking 100% CPU for the process. This
happens for LMTP (where it doesn't matter so much) and also for
submission-login where unauthenticated users can trigger it.

- CVE-2020-7957 (denial of service)

A denial of service have been found in Dovecot before 2.3.9.3, where a
specially crafted e-mail can cause a mailbox to have permanently
inaccessible mail, or the e-mail itself can be stuck in delivery. This
happens because the snippet generation crashes if a message is large
enough that message-parser returns multiple body blocks, the first
block(s) don't contain the full snippet (e.g. full of whitespace) and
the input ends with '>'.

Impact
=====
A remote, unauthenticated user can cause a denial of service via a
crafted message.

References
=========
https://dovecot.org/pipermail/dovecot-news/2020-February/000430.html
https://dovecot.org/pipermail/dovecot-news/2020-February/000431.html
https://security.archlinux.org/CVE-2020-7046
https://security.archlinux.org/CVE-2020-7957