CVE-2020-7247

Confirmed PUBLISHED

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...

OpenBSD · OpenSMTPD

Exploited in the wild PoC available

Recommended Action

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

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Confidence

Confirmed

Exploitation Status

Exploited in the wild

Observed in Sensors

Attempts (30d)

—

Unique Attacker IPs

—

CISA KEV

In CISA KEV

CVSS / EPSS

9.8 Critical

At a Glance

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.

metasploit nuclei_scanner cisa

CVE Published: Jan 29, 2020
Exploitation Reported: Mar 25, 2022
CVSS: 9.8 Critical
EPSS: —

Remote Low complexity No user interaction Unauthenticated

Affected Versions

Vendor	Product	Version	Status
n/a	n/a	n/a	Affected

CVE References

DSA-4611 debian.org · Vendor Advisory https://www.debian.org/security/2020/dsa-4611
USN-4268-1 usn.ubuntu.com · Vendor Advisory https://usn.ubuntu.com/4268-1/
FEDORA-2020-b92d7083ca lists.fedoraproject.org · Vendor Advisory https://lists.fedoraproject.org/archives/list/package-announce%40list...
VU#390745 kb.cert.org · Third-Party Advisory https://www.kb.cert.org/vuls/id/390745
20200129 [SECURITY] [DSA 4611-1] opensmtpd security update seclists.org · Mailing List https://seclists.org/bugtraq/2020/Jan/51

Show 9 more references

20200131 LPE and RCE in OpenSMTPD (CVE-2020-7247) seclists.org · Mailing List http://seclists.org/fulldisclosure/2020/Jan/49
openbsd.org/security.html openbsd.org · CVE Record https://www.openbsd.org/security.html
OSS-Security Mailing List openwall.com · CVE Record http://www.openwall.com/lists/oss-security/2020/01/28/3
GitHub — openbsd/src github.com · CVE Record https://github.com/openbsd/src/commit/9dcfda045474d8903224d175907bfc2...
packetstormsecurity.com/files/156137/OpenBSD-OpenSMTPD-Privilege-Esc... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/156137/OpenBSD-OpenSMTPD-Privile...
packetstormsecurity.com/files/156145/OpenSMTPD-6.6.2-Remote-Code-Exe... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/156145/OpenSMTPD-6.6.2-Remote-Co...
packetstormsecurity.com/files/156249/OpenSMTPD-MAIL-FROM-Remote-Code... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/156249/OpenSMTPD-MAIL-FROM-Remot...
packetstormsecurity.com/files/156295/OpenSMTPD-6.6.1-Local-Privilege... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/156295/OpenSMTPD-6.6.1-Local-Pri...
packetstormsecurity.com/files/162093/OpenBSD-OpenSMTPD-6.6-Remote-Co... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/162093/OpenBSD-OpenSMTPD-6.6-Rem...

Recommended Actions

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
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Known Exploited Vulnerability Sources

Catalogues that list this CVE as a known exploited vulnerability.

Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.

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Source	Added
CISA First	2022-03-25 00:00 UTC

Scanner Artifacts

Nuclei and Metasploit references linked to this CVE.

Scanner	Reference	Detected
Nuclei	https://github.com/projectdiscovery/nuclei-templates/blob/main/javascript/cves/2020/CVE-2020-7247.yaml	Apr 25, 2025
Metasploit	https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/unix/smtp/opensmtpd_mail_from_rce.rb	Apr 28, 2025

CVSS Scores

CVSS v3.1 9.8 Critical

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

CVSS v2.0 10.0 High

AV:N/AC:L/Au:N/C:C/I:C/A:C

Exploitation Status

Exploited in the wild

Recorded 2022-03-25 00:00:00 UTC · CISA

Proof of concept available

Recorded 2020-02-18 10:52:38 UTC · GitHub

Weaknesses (CWE)

CWE-755

Improper Handling of Exceptional Conditions

Scanner Integrations

Scanner	Reference	Detected
Metasploit	https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/unix/smtp/opensmtpd_mail_from_rce.rb	Apr 28, 2025
Nuclei	https://github.com/projectdiscovery/nuclei-templates/blob/main/javascript/cves/2020/CVE-2020-7247.yaml	Apr 25, 2025

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

SimonSchoeni/CVE-2020-7247-POC

github · Created 2021-11-26 17:28:56 UTC · 2 stars

Proof of concept for CVE-2020-7247 for educational purposes.

f4T1H21/CVE-2020-7247

github · Created 2021-06-19 07:34:42 UTC · 2 stars

PoC exploit for CVE-2020-7247 OpenSMTPD 6.4.0 < 6.6.1 Remote Code Execution

bytescrappers/CVE-2020-7247

github · Created 2021-06-02 12:02:33 UTC · 0 stars

This vulnerability exists in OpenBSD’s mail server OpenSMTPD’s “smtp_mailaddr()” function, and affects OpenBSD version 6.6. This allows an attacker to execute arbitrary shell commands like “sleep 66” as root user

QTranspose/CVE-2020-7247-exploit

github · Created 2021-02-13 06:57:47 UTC · 11 stars

OpenSMTPD 6.4.0 - 6.6.1 Remote Code Execution PoC exploit

r0lh/CVE-2020-7247

github · Created 2020-02-18 10:52:38 UTC · 3 stars

Proof Of Concept Exploit for CVE-2020-7247 (Remote Execution on OpenSMTPD < 6.6.2

OpenSMTPD 6.4.0-6.6.1 - Remote Code Execution

nuclei · Created Unknown

opensmtpd_mail_from_rce

metasploit · Created Unknown

Metasploit module for CVE-2020-7247

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Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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Pro API Example

GET /api/v2/pro/kevs/CVE-2020-7247

{
  "cve_id": "CVE-2020-7247",
  "title": "smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6, as used in OpenBSD 6.6 and ...",
  "affected_vendor": "OpenBSD",
  "affected_product": "OpenSMTPD",
  "affected_versions": [
    { "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
  ],
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "epss_score": null,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "...": "Pro API fields" },
  "proof_of_concepts": [ "..." ],
  "scanner_integrations": [ "..." ]
}

The free JSON API returns basic KEV fields only. Confidence, telemetry, and artifact enrichment require Pro API access.

CVE-2020-7247

At a Glance

Affected Versions

CVE References

Recommended Actions

Known Exploited Vulnerability Sources

Scanner Artifacts

Virtual Patch

CVSS Scores

Exploitation Status

Weaknesses (CWE)

Scanner Integrations

Potential Proof of Concepts

Timeline

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