CVE-2020-7247
CriticalExploitedPublic exploitsmtp_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.
Published Jan 29, 2020 · Updated Oct 9, 2026 · Also known as ALPINE-CVE-2020-7247, DEBIAN-CVE-2020-7247, DSA-4611-1, UBUNTU-CVE-2020-7247, USN-4268-1, USN-4875-1
Key Facts
Patch immediately- CVE-2020-7247 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Opensmtpd (Openbsd), Ubuntu Linux (Canonical), Debian Linux and 1 more product.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 25, 2022. Public exploit code is available.
- EPSS estimates a 99% probability of exploitation in the next 30 days.
- Fixed versions are available, including Opensmtpd 5.4.1p1-1ubuntu0.1~esm1, Opensmtpd 5.7.3p2-1ubuntu0.1~esm1, Opensmtpd 5.7.3p2-1ubuntu0.1~esm2.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
99%
Higher than 99.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2020-7247 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 25, 2022 | Apr 15, 2022 | Not reported |
| Industry KEV feed | Mar 25, 2022 | Apr 15, 2022 | Not reported |
| CIRCL KEV | Mar 25, 2022 | Apr 15, 2022 | Not reported |
| ENISA EUVD | Mar 25, 2022 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
39 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OpensmtpdOpenbsd | 6.6 | 6.6.2p1-1 |
| Ubuntu LinuxCanonical | 18.04, 19.10 | n/a |
| Debian LinuxDebian | 10.0, 9.0 | n/a |
| FedoraFedoraproject | 32 | n/a |
Patched Releases
Opensmtpd
5.4.1p1-1ubuntu0.1~esm1, 5.7.3p2-1ubuntu0.1~esm1, 5.7.3p2-1ubuntu0.1~esm2, 6.0.2p1-2+deb9u2, 6.0.3p1-1ubuntu0.1, 6.0.3p1-5+deb10u3, 6.6.2p1-1, 6.6.2p1-r0
Timeline
Publicly disclosed
Jan 29, 2020
Added to CISA KEV
Mar 25, 2022
Added to Industry KEV feed
Mar 25, 2022
Added to CIRCL KEV
Mar 25, 2022
Added to ENISA EUVD
Mar 25, 2022
Last updated
Oct 9, 2026
Weakness Type
- CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
- CWE-755 Improper Handling of Exceptional Conditions
References
- advisoryhttp://packetstormsecurity.com/files/162093/OpenBSD-OpenSMTPD-6.6-Remote-Code-Execution.html
- advisoryhttps://ftp.openbsd.org/pub/OpenBSD/patches/6.6/common/019_smtpd_exec.patch.sig
- advisoryhttps://github.com/OpenSMTPD/OpenSMTPD/commit/be6ef06cba9484d008d9f057e6b25d863cf278ff
- advisoryFEDORA-2020-b92d7083ca
- advisory20200129 [SECURITY] [DSA 4611-1] opensmtpd security update
FAQ
Common Questions.
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.
Affected: Opensmtpd (Openbsd) versions 6.6; Ubuntu Linux (Canonical) versions 18.04, 19.10; Debian Linux versions 10.0, 9.0, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 25, 2022.
Yes. It was added on Mar 25, 2022 with a federal remediation due date of Apr 15, 2022.
Public exploit code is available.
Fixed versions are available, including Opensmtpd 5.4.1p1-1ubuntu0.1~esm1, Opensmtpd 5.7.3p2-1ubuntu0.1~esm1, Opensmtpd 5.7.3p2-1ubuntu0.1~esm2.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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