CVE-2020-7247

Exp

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.

Published: 2020-01-29 Last update: 2025-11-07 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-7247 is rated Critical Active Threat (99.3/100): CVSS Critical severity, with high exploitation likelihood (EPSS 94.08%, 100th percentile). CISA KEV confirms active exploitation (added 2022-03-25) affecting OpenBSD / OpenSMTPD. a weakness (CWE-755) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2020-7247

Name: OpenSMTPD Remote Code Execution Vulnerability · CISA KEV detail

Exploit added: 2022-03-25

Action due: 2022-04-15

Required action: Apply updates per vendor instructions.

Public exploit references (Exploit-DB) for CVE-2020-7247

EDB-ID Source Kind Published Link
48051 exploit_db edb 2020-02-11 Exploit-DB ↗
48038 exploit_db edb 2020-02-10 Exploit-DB ↗
47984 exploit_db edb 2020-01-30 Exploit-DB ↗
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Exploit prediction scoring system (EPSS) score for CVE-2020-7247

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-28 93.98% 94.08% +0.09%
2 2025-12-27 94.13% 93.98% -0.14%
3 2025-11-21 — 94.13% —

Full EPSS history (22 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-7247

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 10.0 [email protected]

Weakness enumeration for CVE-2020-7247

OS Trackers for CVE-2020-7247

vendor priority summary link
alpine — CVE-2020-7247: 1 source package rows (opensmtpd); 11 state rows across 11 repos (3.11-main, 3.12-main, 3.17-community, 3.17-main, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community, edge-main); fixed 11, open 0. https://security.alpinelinux.org/vuln/CVE-2020-7247
debian not yet assigned CVE-2020-7247 not yet assigned priority: Debian including 1 source packages (opensmtpd), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-7247
ubuntu high CVE-2020-7247 high priority: Ubuntu including 1 source packages (opensmtpd), 10 status rows across 10 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): not-affected 5, released 5. https://ubuntu.com/security/CVE-2020-7247

Affected software / configurations for CVE-2020-7247

Vendor Product Version Raw CPE
openbsd opensmtpd 6.6 cpe:2.3:a:openbsd:opensmtpd:6.6:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 19.10 cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*

References for CVE-2020-7247

URL Tags
http://packetstormsecurity.com/files/156137/OpenBSD-OpenSMTPD-Privilege-Escalation-Code-Execution.html Exploit Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/156145/OpenSMTPD-6.6.2-Remote-Code-Execution.html Exploit Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/156249/OpenSMTPD-MAIL-FROM-Remote-Code-Execution.html Exploit Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/156295/OpenSMTPD-6.6.1-Local-Privilege-Escalation.html Exploit Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/162093/OpenBSD-OpenSMTPD-6.6-Remote-Code-Execution.html Broken Link Third Party Advisory VDB Entry
http://seclists.org/fulldisclosure/2020/Jan/49 Exploit Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2020/01/28/3 Exploit Mailing List Third Party Advisory
https://github.com/openbsd/src/commit/9dcfda045474d8903224d175907bfc29761dcb45 Patch
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPH4QU4DNVHA7ACFXMYFCEP5PSXXPN4E/ Mailing List Third Party Advisory
https://seclists.org/bugtraq/2020/Jan/51 Mailing List Third Party Advisory
https://usn.ubuntu.com/4268-1/ Third Party Advisory
https://www.debian.org/security/2020/dsa-4611 Mailing List Third Party Advisory
https://www.kb.cert.org/vuls/id/390745 Third Party Advisory US Government Resource
https://www.openbsd.org/security.html Patch Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-7247 US Government Resource
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