CVE-2020-7247

CVE-2020-7247 is a critical-severity (CVSS 9.8) vulnerability in OpenBSD OpenSMTPD. CISA added it to the Known Exploited Vulnerabilities catalog on March 25, 2022, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by April 15, 2022. CISA does not currently list it as used in ransomware campaigns.

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 vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• http://packetstormsecurity.com/files/156137/OpenBSD-OpenSMTPD-Privilege-Escalation-Code-Execution.html
• http://packetstormsecurity.com/files/156145/OpenSMTPD-6.6.2-Remote-Code-Execution.html
• http://packetstormsecurity.com/files/156249/OpenSMTPD-MAIL-FROM-Remote-Code-Execution.html
• http://packetstormsecurity.com/files/156295/OpenSMTPD-6.6.1-Local-Privilege-Escalation.html
• http://packetstormsecurity.com/files/162093/OpenBSD-OpenSMTPD-6.6-Remote-Code-Execution.html
• http://seclists.org/fulldisclosure/2020/Jan/49
• http://www.openwall.com/lists/oss-security/2020/01/28/3
• https://github.com/openbsd/src/commit/9dcfda045474d8903224d175907bfc29761dcb45