Advisory Details

This vulnerability allows remote attackers to bypass the Mark-of-the-Web protection mechanism on affected installations of Microsoft Windows. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the implementation of OneDrive file syncing. When syncing files from the cloud to the local filesystem, OneDrive neither applies nor preserves the Mark-of-the-Web on files originating from untrusted locations. An attacker can leverage this vulnerability to bypass SmartScreen protection and execute arbitrary code in the context of the current user.

06/06/24 – ZDI reported the vulnerability to the vendor
06/06/24 – the vendor acknowledged the receipt of the report
07/10/24 – the vendor rated the severity of the vulnerability to be Low and communicated that the issues did not meet the bar for immediate servicing
07/31/25 – ZDI notified the vendor of the intention to publish the cases as a 0-day advisory

-- Mitigation: Given the nature of the vulnerability, the only salient mitigation strategy is to restrict interaction with the product.

• 2024-06-06 - Vulnerability reported to vendor
• 2025-08-06 - Coordinated public release of advisory
• 2025-08-06 - Advisory Updated