Nice find, thanks!

I have audited the DevTools protocol today, and looked for privilege escalation in extensions (local file access and privileged code execution), and reported  bug 805445  and bug 805557 .

Given the usefulness of the DevTools protocol, I retract my second suggestion (restricting the DevTools protocol to <=1.2) and recommend to modify the chrome.debugger API to enforce the existing target checks on all methods in the "Target.*" DevTools domain.

This could be an extensions/-only change (validating messages in chrome/browser/extensions/api/debugger/debugger_api.cc).
This may also involve changes the DevTools backend (e.g. adding logic to enforce that clients can only access certain web origins/schemes or processes).

dgozman: Uh oh! This issue still open and hasn't been updated in the last 14 days. This is a serious vulnerability, and we want to ensure that there's progress. Could you please leave an update with the current status and any potential blockers?

If you're not the right owner for this issue, could you please remove yourself as soon as possible or help us find the right one?

If the issue is fixed or you can't reproduce it, please close the bug. If you've started working on a fix, please set the status to Started.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

dgozman: Uh oh! This issue still open and hasn't been updated in the last 29 days. This is a serious vulnerability, and we want to ensure that there's progress. Could you please leave an update with the current status and any potential blockers?

If you're not the right owner for this issue, could you please remove yourself as soon as possible or help us find the right one?

If the issue is fixed or you can't reproduce it, please close the bug. If you've started working on a fix, please set the status to Started.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Friendly ping from the security sheriff. Can we get any update on this?

Now that we have a mechanism of restricted clients in place, this should be easy to fix.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/46f5cfb6414c04b65cba4ec59ca992f338934fc9

commit 46f5cfb6414c04b65cba4ec59ca992f338934fc9
Author: Dmitry Gozman <dgozman@chromium.org>
Date: Mon Apr 02 19:55:26 2018

[DevTools] Do not create target handler for restricted sessions

Bug:  805224 
Change-Id: I08528e44e79d0a097cfe72ab4949dda538efd098
Reviewed-on: https://chromium-review.googlesource.com/988695
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#547496}
[modify] https://crrev.com/46f5cfb6414c04b65cba4ec59ca992f338934fc9/content/browser/devtools/render_frame_devtools_agent_host.cc

This should be fixed now.

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And $2,000 for this report, thanks as ever!

This bug has been closed for more than 14 weeks. Removing security view restrictions.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot