CVE-2020-7247
CRITICALCISA KEVEPSS 100th pctlDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Very high risk: more likely to be exploited than 100% of all known CVEs.
OpenSMTPD Remote Code Execution Vulnerability
smtp_mailaddr in smtp_session.c in OpenSMTPD, as used in OpenBSD and other products, allows remote attackers to execute arbitrary commands as root via a crafted SMTP session.
Apply updates per vendor instructions.
Remediation due: 2022-04-15
References
Related Vulnerabilities
Other CWE-78 (OS Command Injection) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2021-1498 | Critical | 9.8 | 100% | KEV | Fix |
| CVE-2014-6271 | Critical | 9.8 | 100% | KEV | Fix |
| CVE-2019-16920 | Critical | 9.8 | 100% | KEV | - |
| CVE-2022-44877 | Critical | 9.8 | 100% | KEV | Fix |
| CVE-2020-8515 | Critical | 9.8 | 100% | KEV | - |
| CVE-2024-4577 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
Common questions
How do I fix CVE-2020-7247?
Published advisories record a fix for 2 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2020-7247 being actively exploited?
Yes. CVE-2020-7247 is listed in the CISA Known Exploited Vulnerabilities catalog, which means exploitation has been observed in the wild. US federal agencies were required to remediate it by 2022-04-15. Treat it as a priority whatever its CVSS score says.
How severe is CVE-2020-7247?
CVE-2020-7247 has a CVSS v3 base score of 9.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2020-7247 affect?
Published advisories record a fix for opensmtpd (Debian), opensmtpd (Ubuntu). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-07.