GNU Mailutils: unexpected processsing of escape sequences

Background

GNU Mailutils is a collection of mail-related utilities, including an IMAP4 server (imap4d) and a Mail User Agent (mail).

Description

A vulnerability has been discovered in GNU Mailutils. Please review the CVE identifier referenced below for details.

Impact

mail(1) from mailutils would process escape sequences (like ~! shellcommand) in message bodies piped/redirected in. This creates an RCE if some part of the message body is under an attacker’s control.

Workaround

There is no known workaround at this time.

Resolution

All Mailutils users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-mail/mailutils-3.12-r3"