CVE-2020-7247

OpenSMTPD Remote Code Execution Vulnerability

IN CISA KEV

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.

Vendor: OpenBSD
Product: OpenSMTPD
CVSS 3.1: 9.8 (critical), scored by NVD (primary)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1: 9.8 (critical), scored by 134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-78, CWE-755
Published: 2020-01-29
NVD modified: 2026-06-17
NVD status: Analyzed

CISA KEV

Date added: 2022-03-25
Due date: 2022-04-15
Ransomware use: Unknown
Required action: Apply updates per vendor instructions.

EPSS

99.0% chance of exploitation in the next 30 days (percentile 99th)

FIRST EPSS, updated 17 Oct 2026. About EPSS

CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.

References

packetstormsecurity.com (Broken Link, Third Party Advisory, VDB Entry)
github.com (Patch)
lists.fedoraproject.org (Mailing List, Third Party Advisory)
seclists.org (Mailing List, Third Party Advisory)
usn.ubuntu.com (Third Party Advisory)
www.debian.org (Mailing List, Third Party Advisory)
www.kb.cert.org (Third Party Advisory, US Government Resource)
www.openbsd.org (Patch, Vendor Advisory)
packetstormsecurity.com (Broken Link, Third Party Advisory, VDB Entry)
github.com (Patch)
lists.fedoraproject.org (Mailing List, Third Party Advisory)
seclists.org (Mailing List, Third Party Advisory)

Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.