Guest Access Gaffe: Microsoft Teams’ Security Loophole Leaves the Door Open for Cyber Attacks
Cybersecurity researchers have discovered a cross-tenant blind spot in Microsoft Defender for Office 365 protections, allowing attackers to exploit Teams’ guest access feature. This loophole lets attackers create “protection-free zones,” potentially exposing users to phishing and malware. Organizations should tighten B2B settings and educate users on suspicious invitations.
Hot Take:
Oh, Microsoft Teams, you’re like that open house party where everyone can sneak in, but only after ditching their security badge at the door! While the new update is all about making friends, it feels like it’s also about inviting the wrong crowd with zero bouncers in sight. Maybe Teams should consider a guest list with a few more velvet ropes.
Key Points:
- Guest users in Microsoft Teams are governed by the external tenant’s security policies, not their home organization’s.
- A new Teams feature allows users to chat with anyone via email, enabling guest access and bypassing certain security measures.
- Attackers can exploit this by setting up malicious tenants with minimal security, creating “protection-free zones.”
- Emails from Microsoft’s infrastructure can bypass standard email security checks, potentially delivering phishing or malware attacks.
- Organizations should tighten B2B collaboration settings and educate users about unsolicited Teams invites.
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