Reject unsolicited clipboard provides from clients#2126
Closed
hyder365 wants to merge 1 commit into
Closed
Conversation
Track whether a clipboard request is pending and reject clipboardProvide messages that were not explicitly requested. An authenticated client with AccessCutText could previously push arbitrary clipboard content that would reach the desktop clipboard without any request, enabling clipboard spoofing attacks against other connected clients. Also fixes clipboard store-before-check: access rights are now verified before storing clipboard data in both clientCutText() and handleClipboardProvide() paths.
Member
|
A malicious client can do that anyway by pushing announce messages. So I'm not sure what the practical difference is here. What scenario are you targeting that this PR would improve? |
Contributor
Author
|
You're right, a malicious client can just use clipboardNotify to trigger the request and still get its provide accepted. This only blocks the direct push, which isn't much of a win. |
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
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Track whether a clipboard request is pending and reject clipboardProvide messages that were not explicitly requested. An authenticated client could previously push arbitrary clipboard content that would reach the desktop clipboard without any request, enabling clipboard spoofing attacks against other connected clients.\n\nAlso fixes clipboard store-before-check by moving the access rights check before data storage in both clientCutText and handleClipboardProvide paths.