Advisory Details

This vulnerability allows remote attackers to bypass the Mark-of-the-Web protection mechanism on affected installations of Dropbox Desktop. 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 handling of shared folders. When syncing files from a shared folder belonging to an untrusted account, the Dropbox desktop application does not apply the Mark-of-the-Web to the local files. An attacker can leverage this vulnerability to execute arbitrary code in the context of the current user.

06/05/24 – ZDI reported the vulnerability to the vendor.

06/06/24 – The vendor acknowledged the report.

06/10/24 – The vendor states the vulnerability about Mark-of-the-Web is out of scope for their bug bounty program.

06/11/24 – ZDI acknowledged their rejection and informed the vendor that we’re publishing this case as a zero-day advisory on 6/13/24 in accordance with our disclosure policy.

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

• 2024-06-05 - Vulnerability reported to vendor
• 2024-06-13 - Coordinated public release of advisory
• 2024-08-15 - Advisory Updated