Ghost-Sender Flaw Exposes Exchange Online Users to Sender Spoofing Attacks

A newly disclosed “Ghost-Sender” flaw is exposing Microsoft Exchange Online environments to large-scale email spoofing attacks, allowing threat actors to bypass standard email authentication controls and deliver forged messages directly to users’ inboxes. The issue, identified by security researchers Lucas Dodgson, Tobias Oberdörfer, and Robin Hilber, stems from misconfigurations in hybrid or cloud email deployments […]

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