Repository navigation
draft editor: require a per-session token on the loopback server - #177
Open
benjaminkincses wants to merge 2 commits into
Open
benjaminkincses wants to merge 2 commits into
benjaminkincses wants to merge 2 commits into
Conversation
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
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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 draft editor server binds 127.0.0.1 and serves POST /send, which posts to Slack as the user, with no authentication and no Origin check. Any local process can call it, and a web page that can reach loopback can send a cross-origin POST in the shape of a CORS simple request (JSON parsed regardless of content type). The editor stays open up to 30 minutes.
Fix: generate a random per-session token when the editor starts. The editor page is only served when the URL carries the token, the page sends it back as an X-Draft-Token header on /send and /cancel, and POSTs with a mismatched Origin are rejected. Token comparison is constant time.
Verified locally with a stub onSend: cross-origin POST without the token returns 403 and does not send, GET without the token returns 403, the normal editor flow with the token returns 200 and sends.