Direct Send Vulnerability: Risks in Email Systems and How to Prevent Them

A direct send vulnerability occurs when email servers allow messages to be sent without proper authentication, making them a target for abuse. Attackers can exploit this flaw to send spoofed emails, launch phishing campaigns, or distribute malware while appearing to come from trusted domains. Such vulnerabilities often stem from misconfigured SMTP settings or lack of security controls. The consequences include reputational damage, blocked domains, and increased exposure to fraud.

Microsoft 365 Direct Send vulnerability

Microsoft 365’s Direct Send Feature Under Attack: How Cybercriminals Are Bypassing Email Security

Ravi Jain
exposes a significant vulnerability within Microsoft 365's Direct Send feature, explaining how it allows cybercriminals to bypass email security by impersonating internal users. This sophisticated phishing campaign leverages the feature's lack of authentication, enabling attackers to send malicious emails that appear to originate from within an organization, even without compromising any accounts. The article details the technical aspects of the exploit, including the use of PowerShell commands and specific indicators of compromise. Finally, it outlines critical mitigation strategies for organizations, emphasizing enhanced monitoring and advanced email security solutions to combat this difficult-to-detect threat. ... Read More