Summary:
We don't currently validate CSRF tokens on this workflow. This allows an
attacker to upload arbitrary files on the user's behalf. Although I believe the
tight list of servable mime-types means that's more or less the end of the
attack, this is still a vulnerability.
In the long term, the right solution is probably to pass CSRF tokens on all Ajax
requests in an HTTP header (or just a GET param) or something like that.
However, this endpoint is unique and this is the quickest and most direct way to
close the hole.
Test Plan:
- Drop-uploaded files to Files, Maniphest, Phriction and Differential.
- Modified CSRF vaidator to use __csrf__.'x' and verified uploads and form
submissions don't work.
Reviewers: andrewjcg, aran, jungejason, tuomaspelkonen, erling
Commenters: andrewjcg, pedram
CC: aran, epriestley, andrewjcg, pedram
Differential Revision: 758
Summary:
We currently cycle CSRF tokens every hour and check for the last two valid ones.
This means that a form could go stale in as little as an hour, and is certainly
stale after two.
When a stale form is submitted, you basically get a terrible heisen-state where
some of your data might persist if you're lucky but more likely it all just
vanishes. The .js file below outlines some more details.
This is a pretty terrible UX and we don't need to be as conservative about CSRF
validation as we're being. Remedy this problem by:
- Accepting the last 6 CSRF tokens instead of the last 1 (i.e., pages are
valid for at least 6 hours, and for as long as 7).
- Using JS to refresh the CSRF token every 55 minutes (i.e., pages connected
to the internet are valid indefinitely).
- Showing the user an explicit message about what went wrong when CSRF
validation fails so the experience is less bewildering.
They should now only be able to submit with a bad CSRF token if:
- They load a page, disconnect from the internet for 7 hours, reconnect, and
submit the form within 55 minutes; or
- They are actually the victim of a CSRF attack.
We could eventually fix the first one by tracking reconnects, which might be
"free" once the notification server gets built. It will probably never be an
issue in practice.
Test Plan:
- Reduced CSRF cycle frequency to 2 seconds, submitted a form after 15
seconds, got the CSRF exception.
- Reduced csrf-refresh cycle frequency to 3 seconds, submitted a form after 15
seconds, got a clean form post.
- Added debugging code the the csrf refresh to make sure it was doing sensible
things (pulling different tokens, finding all the inputs).
Reviewed By: aran
Reviewers: tuomaspelkonen, jungejason, aran
CC: aran, epriestley
Differential Revision: 660
Summary:
Fixes the issue caused by rPa0af5b66437719dba6136579c051982ab275e6a0. Prior to
that patch, isCommentInNewFile() returned $comment->getIsNewFile(). While this
was often the wrong value, it came from the database and was the integer 1 if
true.
After the patch, the function returns 'true' as a boolean, which is passed to JS
and then back to PHP, interpreted as an integer, and evaluates to 0.
To avoid this issue in general, provide an isBool() method on AphrontRequest
which interprets this correctly.
I will also revert the revert of rPa0af5b66437719dba6136579c051982ab275e6a0 when
I land this.
Test Plan:
Clicked "reply" on the right hand side of a diff, got a right-hand-side inline
comment.
Reviewed By: rm
Reviewers: tuomaspelkonen, jungejason, aran, rm
CC: simpkins, aran, epriestley, rm
Differential Revision: 250
