Oasis Security Research Team Discovers Microsoft Azure MFA Bypass
www.oasis.security
Critical vulnerability could have allowed malicious actors to gain unauthorized access to users’ Microsoft accounts.

Archived

Here is the report (pdf) – (archived)

Oasis Security’s research team uncovered a critical vulnerability in Microsoft’s Multi-Factor Authentication (MFA) implementation, allowing attackers to bypass it and gain unauthorized access to the user’s account, including Outlook emails, OneDrive files, Teams chats, Azure Cloud, and more. Microsoft has more than 400 million paid Office 365 seats, making the consequences of this vulnerability far-reaching.

The bypass was simple: it took around an hour to execute, required no user interaction and did not generate any notification or provide the account holder with any indication of trouble.

[Edit to insert the original link to the Oasis site.]

  • ShadowRam@fedia.io
    5·
    3 days ago

    It was my understanding that the hacker would need physical access to the machine in order to pull this off.

    • jarfil@beehaw.org
      12·
      3 days ago

      No, it’s a MFA bypass. All a hacker needed was the ability to initiate new sessions (after stealing user:pass, for example via malware).