Answers to Security and Privacy Questionnaire
Indirectly: it is conceivable that a user could open sensitive information in a web app, perhaps editing their tax return in a web app made for that purpose.
Yes. It will grant read and write access to some of a user's files (if they choose to open them with a PWA).
3.3 Does this specification introduce new state for an origin that persists across browsing sessions?
No.
Yes, in the form of the contents of the native file system. Note, however, that the user must have both origins installed as PWAs and must explicitly open the same file with both web apps.
3.5 Does this specification expose any other data to an origin that it doesn’t currently have access to?
Yes. The origin may be granted access to files on a user's machine. However, this will be building on top of the native-file-system proposal and is more another avenue for getting access, than completely new data.
Specifically, this will allow native file system access to be granted by choosing to open a file with a web application from the operating system. Previously, native file system access could only be granted by showing a file picker from a web application.
No.
No.
No.
3.9 Does this specification allow an origin access to aspects of a user’s local computing environment?
Yes. This is another avenue of being granted access to certain files in the user's local computing environment. The user explicitly grants permission by a) installing the website and b) choosing to open a file with the installed website.
No.
No, however it does allow an installed app some measure of control over operating system native UI.
No.
Third party contexts will not be able to see files that the first party was launched with.
Sites may not be registered as a file handler unless they are installed, which is not possible in incognito mode. Thus, they will never receive access to any files via this API and cannot expect to (as they are not installed).
Not directly, but once a site has been granted write access to a file it may persist data. The duration of access to files is controlled by the File System Access API.
Yes. See the explainer.
Yes, in that it provides another way for user's to expose files on their native file system to the web.