Microsoft OneDrive File Picker vulnerability grants unauthorized AI and third-party app access
Security researchers at Oasis Security discovered a vulnerability in Microsoft OneDrive's File Picker tool that grants AI services like ChatGPT and third-party applications such as Slack and Trello full access to all files in a user's OneDrive account, even when only sharing a single file. While users must grant permission to use File Picker, the scope of access granted is not clearly disclosed, potentially exposing personal information to AI systems without user awareness.
What happened
Security researchers at Oasis Security discovered that Microsoft OneDrive's File Picker tool grants other applications full access to all files stored in a user's OneDrive account. The File Picker is designed as an interface allowing users to share files from OneDrive through external applications and websites, but requests full account access even when sharing a single file.
While users must grant permission to use File Picker, the scope of comprehensive access granted is not clearly visible to users. Applications including ChatGPT, Slack, and Trello could obtain access to all OneDrive data when users share files through these services.
Reported impact
Users who recently shared files from OneDrive through programs like Slack, Trello, or ChatGPT may have unknowingly granted these applications access to all their stored data. Personal information could be exposed to AI systems without the user's awareness or consent.
Index analysis
The vulnerability stems from the File Picker tool's design, which requires full account permissions to facilitate file sharing, creating a mismatch between the apparent scope of user action and the actual permissions granted.
The issue particularly affects AI services like ChatGPT, which could access personal information users did not intend to share.
Governance controls
Users can revoke permissions by checking their Microsoft Account privacy and security settings to review which applications have access to their OneDrive data and withdraw access rights as needed.
Classification
Sources and evidence
This record was researched and written by the Index, based on the following original reporting.