CVE-2020-7247

Status: AnalyzedCritical (9.8)⚠ Active exploitation

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

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base score: 9.8

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 99%
Percentile among all scored CVEs: 100
Score date: 9/29/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

CISA KEV — actively exploited

Added to catalog: 3/25/2022
Remediation due date: 4/15/2022
Known ransomware use: Unknown

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1190 Exploit Public-Facing Applicationinitial access95 %
Primary impactT1059 Command and Scripting Interpreterexecution90 %
Secondary impactT1498.002 Reflection Amplificationimpact40 %

CWE-78 command injection en servicio SMTP expuesto (AV:N/AC:L/PR:N) permite ejecución de comandos como root. Metacaracteres en MAIL FROM demuestran RCE; ransomware indica potencial DoS.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Privileged Account Management Filter Network Traffic Vulnerability Scanning Restrict Web-Based Content Network Segmentation Limit Software Installation

Affected technologies (4)

Canonical — Ubuntu Linux Debian — Debian Linux Fedoraproject — Fedora Openbsd — Opensmtpd

CWEs

CWE-78, CWE-755
CWE-755

References

Raw JSON (NVD)

Show

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