Cybersecurity researchers have found a security flaw in Microsoft’s OneDrive File Picker that, if efficiently exploited, might enable web sites to entry a person’s whole cloud storage content material, versus simply the recordsdata chosen for add by way of the instrument.
“This stems from overly broad OAuth scopes and deceptive consent screens that fail to obviously clarify the extent of entry being granted,” the Oasis Analysis Staff mentioned in a report shared with The Hacker Information. “This flaw might have extreme penalties, together with buyer information leakage and violation of compliance rules.”
It is assessed that a number of apps are affected, comparable to ChatGPT, Slack, Trello, and ClickUp, given their integration with Microsoft’s cloud service.
The issue, Oasis mentioned, is the results of extreme permissions requested by the OneDrive File Picker, which seeks learn entry to the complete drive, even in circumstances solely a single file is uploaded as a result of absence of fine-grained OAuth scopes for OneDrive.
Compounding issues additional, the consent immediate customers are introduced with previous to a file add is imprecise and doesn’t adequately convey the extent of entry being granted, thereby exposing customers to sudden security dangers.
“The shortage of fine-grained scopes makes it unimaginable for customers to tell apart between malicious apps that focus on all recordsdata and legit apps that ask for extreme permissions just because there isn’t any different safe possibility,” Oasis famous.
The New York-based security firm additional identified that the OAuth tokens used to authorize entry are sometimes saved insecurely, including they’re saved within the browser’s session storage in plaintext format.
One other potential pitfall is that the authorization workflows can also contain issuing a refresh token, granting the appliance ongoing entry to person information by permitting it to get new entry tokens with out having to ask the person to log in once more when the present token expires.
Following accountable disclosure, Microsoft has acknowledged the issue, though there isn’t any repair as but. Within the interim, it is value contemplating quickly eradicating the choice to add recordsdata utilizing OneDrive by way of OAuth till a safe various is in place. Alternately, it is suggested to keep away from utilizing refresh tokens and retailer entry tokens in a safe method and do away with them when now not wanted.
The Hacker Information has reached out to Microsoft for additional remark, and we are going to replace the story if we hear again.
“The shortage of fine-grained OAuth scopes mixed with Microsoft’s imprecise person immediate is a harmful mixture that places each private and enterprise customers in danger,” Oasis mentioned. “This discovery reinforces the significance of steady vigilance in OAuth scope administration, common security assessments, and proactive monitoring to guard person information.”
