Profile: CVE-2020-7247

CVE-2020-7247

Product Serial: P-2022-10-25a

TLP:GREEN

In this profile, ZeroFox Intelligence discusses the risk CVE-2020-7247 poses while covering the technical details and providing a Sigma rule for detection.

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Scope Note

ZeroFox Intelligence is derived from a variety of sources, including—but not limited to—curated open-source accesses, vetted social media, proprietary data sources, and direct access to threat actors and groups through covert communication channels. Information relied upon to complete any report cannot always be independently verified. As such, ZeroFox applies rigorous analytic standards and tradecraft in accordance with best practices and includes caveat language and source citations to clearly identify the veracity of our Intelligence reporting and substantiate our assessments and recommendations. All sources used in this particular Intelligence product were identified prior to 4:30 PM (EDT) on October 7, 2022; per cyber hygiene best practices, caution is advised when clicking on any third-party links.

Executive Summary

When used in OpenBSD 6.6 and other products, smtp_mailaddr in smtp_session.c in OpenSMTPD 6.6.1 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.