CVE-2020-7247

Name: CVE-2020-7247
Creator: NVD / NIST
Published: 2020-01-29T16:15:12.897+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10Actively ExploitedEPSS 98.97%

Last modified Jun 17, 2026

CVE-2020-7247 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 98.97% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

98.97%

99.9th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Apr 15, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
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

References

http://packetstormsecurity.com/files/156137/OpenBSD-OpenSMTPD-Privilege-Escalation-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/156145/OpenSMTPD-6.6.2-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/156249/OpenSMTPD-MAIL-FROM-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/156295/OpenSMTPD-6.6.1-Local-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/162093/OpenBSD-OpenSMTPD-6.6-Remote-Code-Execution.htmlBroken Link, Third Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2020/Jan/49Exploit, Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/01/28/3Exploit, Mailing List, Third Party Advisory
https://github.com/openbsd/src/commit/9dcfda045474d8903224d175907bfc29761dcb45Patch
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPH4QU4DNVHA7ACFXMYFCEP5PSXXPN4E/Mailing List, Third Party Advisory
https://seclists.org/bugtraq/2020/Jan/51Mailing List, Third Party Advisory
https://usn.ubuntu.com/4268-1/Third Party Advisory
https://www.debian.org/security/2020/dsa-4611Mailing List, Third Party Advisory
https://www.kb.cert.org/vuls/id/390745Third Party Advisory, US Government Resource
https://www.openbsd.org/security.htmlPatch, Vendor Advisory
http://packetstormsecurity.com/files/156137/OpenBSD-OpenSMTPD-Privilege-Escalation-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/156145/OpenSMTPD-6.6.2-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/156249/OpenSMTPD-MAIL-FROM-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/156295/OpenSMTPD-6.6.1-Local-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/162093/OpenBSD-OpenSMTPD-6.6-Remote-Code-Execution.htmlBroken Link, Third Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2020/Jan/49Exploit, Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/01/28/3Exploit, Mailing List, Third Party Advisory
https://github.com/openbsd/src/commit/9dcfda045474d8903224d175907bfc29761dcb45Patch
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPH4QU4DNVHA7ACFXMYFCEP5PSXXPN4E/Mailing List, Third Party Advisory
https://seclists.org/bugtraq/2020/Jan/51Mailing List, Third Party Advisory
https://usn.ubuntu.com/4268-1/Third Party Advisory
https://www.debian.org/security/2020/dsa-4611Mailing List, Third Party Advisory
https://www.kb.cert.org/vuls/id/390745Third Party Advisory, US Government Resource
https://www.openbsd.org/security.htmlPatch, Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-7247US Government Resource

Timeline

Published: Jan 29, 2020
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2020-7247?

How severe is CVE-2020-7247?

CVE-2020-7247 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 98.97% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2020-7247?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-7247?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST