A mutt security update has been released for Arch Linux.

ASA-202101-43: mutt: denial of service

Arch Linux Security Advisory ASA-202101-43
=========================================
Severity: Low
Date : 2021-01-29
CVE-ID : CVE-2021-3181
Package : mutt
Type : denial of service
Remote : Yes
Link :   https://security.archlinux.org/AVG-1476

Summary
======
The package mutt before version 2.0.5-1 is vulnerable to denial of
service.

Resolution
=========
Upgrade to 2.0.5-1.

# pacman -Syu "mutt>=2.0.5-1"

The problem has been fixed upstream in version 2.0.5.

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

Description
==========
rfc822.c in Mutt through 2.0.4 allows remote attackers to cause a
denial of service (mailbox unavailability) by sending email messages
with sequences of semicolon characters in RFC822 address fields (aka
terminators of empty groups). A small email message from the attacker
can cause large memory consumption, and the victim may then be unable
to see email messages from other persons.

Impact
=====
A malicious user could send a malformed email that would crash the
application.

References
=========
  https://www.openwall.com/lists/oss-security/2021/01/17/2
  https://gitlab.com/muttmua/mutt/-/issues/323
  https://gitlab.com/muttmua/mutt/uploads/ecd287245a2d0ac0108797eab2f1a224/rfc822_parse_adrlist.txt
  https://gitlab.com/muttmua/mutt/-/commit/4a2becbdb4422aaffe3ce314991b9d670b7adf17
  https://security.archlinux.org/CVE-2021-3181