CVE-2020-7247: OpenSMTPD Remote Code Execution Vulnerability

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2022-03-25. EPSS: 99% chance of exploitation in the next 30 days.

smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, as demonstrated by shell metacharacters in a MAIL FROM field. This affects the "uncommented" default configuration. The issue exists because of an incorrect return value upon failure of input validation.

Affected products

• Canonical Ubuntu Linux: version 18.04 only; version 19.10 only
• Debian Debian Linux: version 9.0 only; version 10.0 only
• Fedoraproject Fedora: version 32 only
• OpenBSD OpenSMTPD: version 6.6 only

Published 2020-01-29. Last modified 2026-06-17.