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.]
Wait until an internal leak reveals how this was a self-backdoored/malware vulnerability.
I will probably get down voted for this comment (because conspiracy?) but in a few years we will see a lot a pikachu faced memes about it. Can’t wait to laugh my ass off.
Did you read the article? Nobody in their right mind would introduce a backdoor like this. This is incompetence
There’s no reason to self-backdoor the authentication mechanism if you already have access to the account’s data. Also it sounds like you are very smart.