CVE-2020-7247Known exploitationPublic exploitNetwork attack vector

Root command execution via MAIL FROM injection

Published Jan 29, 2020 · Updated Oct 21, 2025

OpenSMTPD 6.6 command injection allows remote attackers to execute arbitrary commands as root via a crafted SMTP session. The smtp_mailaddr function in smtp_session.c mishandles failed MAIL FROM validation, allowing shell metacharacters to reach command execution in the uncommented default configuration. The attack requires network access to the SMTP service but no authentication or user interaction, and can compromise confidentiality, integrity, and availability.

CVSS severity9.8
Critical
EPSS probability98.97%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OpenSMTPD 6.6 command injection allows remote attackers to execute arbitrary commands as root via a crafted SMTP session. The smtp_mailaddr function in smtp_session.c mishandles failed MAIL FROM validation, allowing shell metacharacters to reach command execution in the uncommented default configuration. The attack requires network access to the SMTP service but no authentication or user interaction, and can compromise confidentiality, integrity, and availability.

The record

CVE
CVE-2020-7247
Published
Jan 29, 2020
Updated
Oct 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-252, CWE-78, T1059.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 29, 2020CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0NVDAV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-252Unchecked Return Value
CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Command and Scripting Interpreter: Unix Shell

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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