Debian: DSA-4590-1 Critical: cyrus-imapd ACL Bypass Flaw

It was discovered that the lmtpd component of the Cyrus IMAP server
created mailboxes with administrator privileges if the "fileinto" was
used, bypassing ACL checks.

For the oldstable distribution (stretch), this problem has been fixed
in version 2.5.10-3+deb9u2.

For the stable distribution (buster), this problem has been fixed in
version 3.0.8-6+deb10u3.

We recommend that you upgrade your cyrus-imapd packages.

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

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