CVE-2020-7247

CVE-2020-7247 is a critical-severity vulnerability in Openbsd Opensmtpd with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2022-03-25). The underlying weakness is classified as CWE-78.

Key facts

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.

Frequently asked questions

What is CVE-2020-7247?
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 severe is CVE-2020-7247?
CVE-2020-7247 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-7247 being actively exploited?
Yes. CVE-2020-7247 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2022-03-25, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2020-7247?
CVE-2020-7247 primarily affects Openbsd Opensmtpd. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-7247?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2020-7247 have an EU (EUVD) identifier?
Yes. CVE-2020-7247 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-28374. It is also flagged as exploited in the EUVD (since 2022-03-25).
When was CVE-2020-7247 published?
CVE-2020-7247 was published on 2020-01-29 and last updated on 2026-06-17.

References

Affected products (6)

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