Dovecot before version 2.2.29 is vulnerable to a denial of service. When 'dict' passdb and userdb were used for user authentication, the username sent by the IMAP/POP3 client was sent through var_expand() to perform %variable expansion. Sending specially crafted %variable fields could result in excessive memory usage causing the process to crash (and restart), or excessive CPU usage causing all authentications to hang.
CVSS Details
- CVSS 3.1 Base Score: 3.7
- CVSS 3.0 Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Arch Linux | — | Upgrade to the latest version of Arch Linux | Jul 11, 2025 | Jun 21, 2018 |
| Debian | — | Upgrade dovecot | Apr 12, 2017 | Apr 10, 2017 |
| Freebsd | — | Upgrade dovecot2Upgrade dovecot | May 2, 2017 | Apr 30, 2017 |
| Suse | — | Upgrade dovecot22Upgrade dovecotUpgrade dovecot22-develUpgrade dovecot22-backend-sqliteUpgrade dovecot22-backend-pgsqlUpgrade dovecot22-backend-mysql | May 11, 2017 | Apr 10, 2017 |
| Ubuntu | — | Upgrade dovecot-core | Apr 11, 2017 | Apr 10, 2017 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub