A mutt security update has been released for Debian GNU/Linux 9 LTS to address an issue where remote attackers can cause a denial of service by sending email messages with sequences of semicolon characters in RFC822 address fields.

DLA 2529-1: mutt security update

- -----------------------------------------------------------------------
Debian LTS Advisory DLA-2529-1 debian-lts@lists.debian.org
  https://www.debian.org/lts/security/ Utkarsh Gupta
January 21, 2021   https://wiki.debian.org/LTS
- -----------------------------------------------------------------------

Package : mutt
Version : 1.7.2-1+deb9u5
CVE ID : CVE-2021-3181
Debian Bug : 980326

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.

For Debian 9 stretch, this problem has been fixed in version
1.7.2-1+deb9u5.

We recommend that you upgrade your mutt packages.

For the detailed security status of mutt please refer to
its security tracker page at:
  https://security-tracker.debian.org/tracker/mutt

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at:   https://wiki.debian.org/LTS