CISA KEV · Known exploitedCritical

CVE-2020-7247

OpenBSD OpenSMTPD

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: 9.8
EPSS: 98.9%
CISA KEV: Listed
Published: 2020.01.30

PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV

Exploit probability98.9%

Technical severityCVSS 9.8

Vulnerability overview

Affected product and versions

Product: OpenBSD OpenSMTPD
Affected versions: 6.6, 9.0, 10.0, 32, 18.04, 19.10
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

CISA required action

Apply updates per vendor instructions.

Due date: 2022.04.15

1
Identify
Confirm that OpenBSD OpenSMTPD and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-755, CWE-78
KEV added: 2022.03.25
Ransomware use: 미확인