GNU Mailutils: Privilege escalation

Background

The GNU Mailutils are a collection of mail-related utilities, including an IMAP4 server (imap4d).

Description

GNU Mailutils runs maidag by default with setuid root permissions.

Impact

An attacker can use this to write to arbitrary files as root.

Workaround

There is no known workaround at this time.

Resolution

All GNU Mailutils users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-mail/mailutils-3.8"