Repository navigation
Conversation
The toggler is rendered in the topbar on every page and changes state on GET, so crawlers and link prefetchers follow it and flip the visitor's VAT preference as a side effect of merely indexing or hovering the site. rel="nofollow" keeps well behaved crawlers off it. Claude-Session: https://claude.ai/code/session_01P9NzuVPQGvaVR97HZFq98a
15 tasks
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The toggler is rendered in the topbar on every page and changes state on
GET. That means crawlers and link prefetchers follow it and flip the visitor's VAT preference as a side effect of just indexing or hovering the site. It is also trivially triggerable cross-site with<img src=".../toggle-vat">.rel="nofollow"keeps well behaved crawlers off it, which is the bulk of the practical problem.On the deeper fix: the textbook answer is a
POSTform with a CSRF token. I deliberately did not do that here because the route is public API — changing it fromGETtoPOSTbreaks anyone who has linked to it or built their own toggler, so it wants to be a conscious decision rather than a drive-by. Worth noting the impact if someone does trigger it cross-site is limited to flipping a display preference, with no access to anything and nothing destructive. Happy to follow up with thePOSTversion if you want it.Addresses the first security item in #5.
https://claude.ai/code/session_01P9NzuVPQGvaVR97HZFq98a