CVE-2020-8621: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 3% chance of exploitation in the next 30 days.

In BIND 9.14.0 -> 9.16.5, 9.17.0 -> 9.17.3, If a server is configured with both QNAME minimization and 'forward first' then an attacker who can send queries to it may be able to trigger the condition that will cause the server to crash. Servers that 'forward only' are not affected.

Affected products

• Canonical Ubuntu Linux: version 16.04 only; version 18.04 only; version 20.04 only
• ISC BIND: from 9.14.0, up to and including 9.16.5; from 9.17.0, up to and including 9.17.3
• Netapp Steelstore Cloud Integrated Storage: affected versions not specified
• Opensuse Leap: version 15.1 only; version 15.2 only
• Synology DNS Server: before 2.2.2-5027 (fixed in 2.2.2-5027)

Published 2020-08-21. Last modified 2026-06-17.