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CVE-2020-7247

OpenSMTPD Remote Code Execution

9.8 CRITICALActively exploited (CISA KEV)Public exploitEPSS 99.0%
  1. Published29 Jan 2020
  2. Added to CISA KEV25 Mar 2022
  3. Remediation due15 Apr 2022
Actively exploited (CISA KEV)

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.

Added to KEV: 25 Mar 2022Federal remediation due: 15 Apr 2022

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 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

OpenBSD Opensmtpd6.6
Canonical Ubuntu Linux18.04 · 19.10
Debian Linux10.0 · 9.0
Fedoraproject Fedora32

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

and 5 more references

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Frequently asked

Is CVE-2020-7247 being actively exploited?

Yes. CVE-2020-7247 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 25 Mar 2022.

How severe is CVE-2020-7247?

CVE-2020-7247 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 99.0% probability of exploitation.

Which products are affected by CVE-2020-7247?

Affected products include OpenBSD Opensmtpd, Canonical Ubuntu Linux, Debian Linux, Fedoraproject Fedora.

How do I fix CVE-2020-7247?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2020-7247 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, a risk for it never ranks below high, and the update that fixes it moves to the Emergency patch lane. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.