CVE-2020-7247: OpenSMTPD Remote Code Execution Vulnerability

Published Jan 29, 2020
·
Updated

Last updated 25 August 2025

Other sources

smtpmailaddr in smtpsession.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.

Launchpad

smtpmailaddr in smtpsession.c in OpenSMTPD, as used in OpenBSD and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session.

CISA

Affected Software

8 affected componentsFixes available
OpenBSD OpenSMTPD
OpenBSD OpenSMTPD=6.6
Debian Debian Linux=9.0
Debian Debian Linux=10.0
Fedoraproject Fedora=32
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=19.10
debian/opensmtpd
6.8.0p2-36.8.0p2-47.6.0p1-17.8.0p0-2

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/opensmtpd to a version that resolves this vulnerability.

    Fixed in 6.8.0p2-3Fixed in 6.8.0p2-4Fixed in 7.6.0p1-1Fixed in 7.8.0p0-2

Event History

Jan 29, 2020
CVE Published
via MITRE·03:53 PM
Data Sourced
via MITRE·03:53 PM
Description
Data Sourced
via NVD·04:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Mar 25, 2022
Known Exploited
via CISA·12:00 AM
Sep 14, 2025
Data Sourced
via Ubuntu·12:07 AM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Launchpad·12:08 AM
Description
Jan 14, 2026
Data Sourced
via Debian·07:51 AM
DescriptionAffected Software
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Frequently Asked Questions

1

What is CVE-2020-7247?

CVE-2020-7247 is a remote code execution vulnerability in OpenSMTPD.

2

How does CVE-2020-7247 work?

CVE-2020-7247 allows remote attackers to execute arbitrary commands as root via a crafted SMTP session, using shell metacharacters in a MAIL FROM field.

3

What is the severity of CVE-2020-7247?

CVE-2020-7247 has a severity rating of 9.8 (Critical).

4

Which software products are affected by CVE-2020-7247?

OpenSMTPD 6.6 in OpenBSD 6.6 and other products are affected by CVE-2020-7247.

5

How can I fix CVE-2020-7247?

To fix CVE-2020-7247, you should update to the patched version of OpenSMTPD provided by your vendor or distribution.

Contact

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