VulnerabilityAnalyzed

CVE-2020-7247

OpenSMTPD Remote Code Execution Vulnerability

KEVEXPLOIT ×3 ✓CRITICAL 9.8EPSS 99.0%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 15 April 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

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.

CVSS 3.1: 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 98.97% probability · 100th percentile
Public exploits: 3 in Exploit-DB · verified · first 30 January 2020
CISA KEV: Listed 25 March 2022 · due 15 April 2022
Weakness: CWE-78, CWE-755
Affected: openbsd/opensmtpd · debian/debian linux · fedoraproject/fedora · canonical/ubuntu linux
Source: cve@mitre.org

EPSS trend

EPSS 99.0% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2020-7247

Public exploits (3)

Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.

EDB-ID	Title	Type	Published	Verified
EDB-48051 source ↗	OpenSMTPD 6.4.0 < 6.6.1 - Local Privilege Escalation + Remote Code Executionopenbsd · Marco Ivaldi	remote	11 February 2020	yes
EDB-48038 source ↗	OpenSMTPD - MAIL FROM Remote Code Execution (Metasploit)linux · Metasploit	remote	10 February 2020	yes
EDB-47984 source ↗	OpenSMTPD 6.6.1 - Remote Code Executionlinux · 1F98D	remote	30 January 2020	yes

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

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.