CVE-2020-12673: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 6.2% chance of exploitation in the next 30 days.

In Dovecot before 2.3.11.3, sending a specially formatted NTLM request will crash the auth service because of an out-of-bounds read.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 18.04 only; version 20.04 only
• Debian Debian Linux: version 9.0 only; version 10.0 only
• Dovecot Dovecot: before 2.3.11.3 (fixed in 2.3.11.3)
• Fedoraproject Fedora: version 31 only; version 32 only; version 33 only

Published 2020-08-12. Last modified 2026-06-17.