#909: Permissions Policy Reporting and Report-Only mode

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Opened Oct 17, 2023

こんにちは TAG-さん!

I'm requesting a TAG review of Permissions Policy Reporting.

A document's permissions policy sets limits on what kinds of actions it can perform; what APIs are available. When a page tries to do something that is blocked by policy, the browser currently surfaces a message in developer tools -- this can be great when developing a site, but is often not enough when dealing with a site in production. It would be very useful to be able to collect reports about real problems that users are seeing.

We're addressing this by integrating permissions policy with the Reporting API. In the same way that sites can opt in to receiving reports about CSP violations or deprecations, they will now be able to receive reports about permissions policy violations in the wild.

Further details:

  • I have reviewed the TAG's Web Platform Design Principles
  • Relevant time constraints or deadlines: [please provide]
  • The group where the work on this specification is currently being done: W3C (WebAppSec WG)
  • The group where standardization of this work is intended to be done (if current group is a community group or other incubation venue): Same
  • Major unresolved issues with or opposition to this specification: None that I'm aware of. This has been discussed positively in the WG several times.
  • This work is being funded by: Google

You should also know that...

  • Permissions Policy (née Feature Policy) has been reviewed by the TAG, as has the Reporting API. This review request is for the integration of the two, so that policy violations (and potential violations) can trigger reports.

We'd prefer the TAG provide feedback as (please delete all but the desired option):

🐛 open issues in our GitHub repo for each point of feedback

² A Security and Privacy questionnaire helps us understand potential security and privacy issues and mitigations for your design, and can save us asking redundant questions. See https://www.w3.org/TR/security-privacy-questionnaire/.

Discussions

2023-11-20

Minutes

Hadley: report-only mode - that feels like a fingerprinting thing... sending a lot of info without the user being aware of it... Could it be misused?

Yves: you could intentionally generate errors... But probably other ways of doing that... especially if there is a possibility of sending the report to another host...

Peter: most things - like CSP - let you send it to a 3rd party service... some require it.

we discuss writing a comment to ask what abuse scenarios there are and what mitigations might exist?

Peter: the same information can be gotten via an API https://w3c.github.io/permissions/

2023-12-18

Minutes

Dan: waiting for their response - wrote comment asking for update

2024-01-08

Minutes

Hadley: they responded to us ... I'm a little concerned that Ian doesn't know of any unintended consequences...

Dan: we've raised the issue ...

Hadley: we can't make him explore the unintended consequences...

discussion of security & privacy

Sangwhan: i don't think this exposes additional bits of entropy... if you have prior knowledge of what features are available in a UA then you have same level of bits... however you'll get more info about the user and be able to triangulate the user better.. but don't know if this exposes extra info on that regard.

Hadley: that sounds consistent with Ian's review.

discussion on how to push

Sangwhan: it's not going to have multi-stakeholder support since permission policy is a chrome-only feature...

Dan: we should talk about this... why does permission policy not have better support?

Dan: suggest we close this as satisfied with concerns where the "concerns" are multi-implementer support.

Hadley: sounds sensible.

Sangwhan: feature / permission policy did have multi-stakeholder support... just hasn't been implemented... We could ask again... [So I'd prefer "satisfied"]

Hadley: but that's a signal... We have other labels to indicate "please don't do this"...

Sangwhan: sometimes implementers aren't building it but not against it ...

Hadley: important for us to champion multi-implementer support... a web that's interoperable...

<blockquote>

We would really appreciate if you could do some additional review about unintended privacy consequences... Could that work happen in WebAppSec maybe?

We remain concerned about lack of multi-implementer support for Permission Policy itself, as well as this proposal. Although this is out of scope for this review, it remains a general concern. We'd like to encourage you to continue the multi-implementer discussions for permission policy. Also do we have any indication of support from other implementers or stakeholders on this specific proposal?

</blockquote>

Dan: ok we can come back to it in the plenary.

2024-01-15

Minutes

Dan: doesn't look like there has been a reply to us. Should this be with concerns? We need to probe more about what Mozilla's views are on this proposal, and their approach to permission policy

Hadley: agree

2024-02-26

Minutes

bumped

2024-03-25

Minutes

Dan: I will reach out to Chris Harrelson

Max: they promised to update the explainer to analyze unintended consequences and also the party who receives the report... but no update yet.

Dan: leaves note on issue

2024-05-20

Minutes

Dan: sends a note to Chris Harrelson to see if there has been any update

2024-06-17

Minutes

Dan leaves comment