Security Review Request for CSS Color Adjust Level 1

CSS WG requests formal review of CSS Color Adjustment Module Level 1
   https://www.w3.org/TR/css-color-adjust-1/

This module introduces a model and controls over automatic color adjustment by 
the user agent to handle user preferences, such as "Dark Mode", contrast 
adjustment, or specific desired color schemes.

These features work together with related features in Media Queries 5 
<https://www.w3.org/TR/mediaqueries-5/> and the system colors in CSS Color 4 
<https://www.w3.org/TR/css-color-4/#css-system-colors>:
   * media queries allow the author to query the UA
   * color-adjust properties allow the author to give hints to the UA
   * system colors allow the author to use colors from the forced palette

See these minutes for an overview and explainer for forced colors mode 
(corresponds to Microsoft’s “Windows High Contrast Mode”):
   https://lists.w3.org/Archives/Public/www-style/2019Apr/0004.html

This spec is in the "Refining" stage of development, per
   http://fantasai.inkedblade.net/weblog/2011/inside-csswg/process
and is being actively implemented by browsers.

The Privacy and Security Considerations section is here:
  https://www.w3.org/TR/css-color-adjust-1/#priv-sec

Please raise any issues in the csswg GitHub repo:
    https://github.com/w3c/csswg-drafts/issues
and let us know when you have completed your review.

Thanks!

= Self-Review Questionnaire: Security and Privacy =

2.1 What information might this feature expose to Web sites or other parties, 
and for what purposes is that exposure necessary?

The user's preferred color palette is exposed through getComputedStyle in 
forced color mode and also if the author uses any system color keywords.

The use of these colors is necessary, otherwise it's impossible to honor those 
preferences.

2.2 Is this specification exposing the minimum amount of information necessary 
to power the feature?

Currently under debate, see https://github.com/w3c/csswg-drafts/issues/5710
We could lie to the web page about the actual color used, but this has the 
potential to make the page unreadable if the author is using those answers to 
set its own colors.

2.3 How does this specification deal with personal information or 
personally-identifiable information or information derived thereof?

Not applicable

2.4 How does this specification deal with sensitive information?

Not applicable

2.5 Does this specification introduce new state for an origin that persists 
across browsing sessions?

No

2.6 What information from the underlying platform, e.g. configuration data, is 
exposed by this specification to an origin?

Preferred color palette is exposed.

2.7 Does this specification allow an origin access to sensors on a user’s device

No

2.8 What data does this specification expose to an origin? Please also 
document what data is identical to data exposed by other features, in the same 
or different contexts.

Preferred color palette is exposed.

2.9 Does this specification enable new script execution/loading mechanisms?

No

2.10 Does this specification allow an origin to access other devices?

No

2.11 Does this specification allow an origin some measure of control over a 
user agent’s native UI?

No

2.12 What temporary identifiers might this this specification create or expose 
to the web?

None

2.13 How does this specification distinguish between behavior in first-party 
and third-party contexts?

Not applicable

2.14 How does this specification work in the context of a user agent’s Private 
Browsing or "incognito" mode?

No difference

2.15 Does this specification have a "Security Considerations" and "Privacy 
Considerations" section?

Yes https://drafts.csswg.org/css-color-adjust-1/#priv-sec

2.16 Does this specification allow downgrading default security characteristics?

No

2.17 What should this questionnaire have asked?

Nothing springs to mind.

Received on Monday, 7 December 2020 19:47:13 UTC