1549730 - Should preferences be read from default branch only?

Status: RESOLVED FIXED

(Firefox :: Remote Settings Client, enhancement)

Description

[Mathieu Leplatre [:leplatrem]]

We should check if we have some preferences that are not meant to be changed by users, by web extensions, or during runtime.

Those could be read from default branch only.

For example, services.settings.poll_interval is set to 24H. We can imagine using Normandy to change it and increase the frequency. But we never did, and having this value as a pref opens the possibility for an attacker to change the value and disable updates.

https://searchfox.org/mozilla-central/rev/e7d9a8749303b39dadcc0e18ea0d60a570a68145/services/settings/servicesSettings.manifest#5

Comment 1

[Mathieu Leplatre [:leplatrem]]

Apparently, there is a way to set min/max values for timer intervals: https://bugzilla.mozilla.org/show_bug.cgi?id=1315505

We could set min/max to 1H / 72H or anything that's not more than a week.

As for preferences, the only 2 that we never change at run-time are:

• services.settings.changes.path
• services.settings.default_signer

And they could both become constants.

All other prefs are used to store state between sessions (last Etag etc.) or by the Remote Settings Dev Tools to switch environments (eg. Server)

Comment 2

[Mathieu Leplatre [:leplatrem]]

Attachment: Bug 1549730 - Add guardrails for Remote Settings preferences

Comment 3

[Mathieu Leplatre [:leplatrem]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=f034eece15562617bcef5e588898bf544f683025

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8553fd10ee89
Add guardrails for Remote Settings preferences r=glasserc

Comment 5

[Raul Gurzau (:RaulG)]

https://hg.mozilla.org/mozilla-central/rev/8553fd10ee89