Repository navigation
[3.8] gh-108310: Fix CVE-2023-40217: Check for & avoid the ssl pre-close flaw - #108321
Merged
ambv merged 1 commit intoAug 22, 2023
Merged
ambv merged 1 commit into
ambv merged 1 commit into
Conversation
Copy link
Copy Markdown
Contributor
Sorry, something went wrong.
…ose flaw Instances of `ssl.SSLSocket` were vulnerable to a bypass of the TLS handshake and included protections (like certificate verification) and treating sent unencrypted data as if it were post-handshake TLS encrypted data. The vulnerability is caused when a socket is connected, data is sent by the malicious peer and stored in a buffer, and then the malicious peer closes the socket within a small timing window before the other peers’ TLS handshake can begin. After this sequence of events the closed socket will not immediately attempt a TLS handshake due to not being connected but will also allow the buffered data to be read as if a successful TLS handshake had occurred. Co-Authored-By: Gregory P. Smith [Google LLC] <greg@krypto.org>
2 tasks done
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Instances of ssl.SSLSocket were vulnerable to a bypass of the TLS handshake and included protections (like certificate verification) and treating sent unencrypted data as if it were post-handshake TLS encrypted data.
The vulnerability is caused when a socket is connected, data is sent by the malicious peer and stored in a buffer, and then the malicious peer closes the socket within a small timing window before the other peers’ TLS handshake can begin. After this sequence of events the closed socket will not immediately attempt a TLS handshake due to not being connected but will also allow the buffered data to be read as if a successful TLS handshake had occurred.