Mitigate decompression bombs DoS #7964
Open
+92
−19
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
Author
|
@mhils This is the PR mentioned in that advisory. Please take a look :) |
mhils
reviewed
Jan 2, 2026
Member
mhils
left a comment
There was a problem hiding this comment.
Thanks for the PR and sorry for the slow turnaround! Overall I'm happy to add this DoS mitigation, but I don't think it warrants a new property on HttpMessage. Can we just use an option and access that directly please?
Author
|
Could you please expand on that? This feature needs size limit settings from context options. But it seems that not all places that decode http messages have access to the current context. |
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Outdated suggestions cannot be applied.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.
Description
mitmproxy does not limit the size and memory consumption when decoding http messages bodies. Clients or servers can easily crash mitmproxy by sending a single request/response with highly compressed data via proxy.
This pr makes mitmproxy use
body_size_limitin option to limit decompressed body size of incoming http messages, protecting it from zip bombs DoS attacks.http bodies decoding now raises
ValueErroras decoding fails if decompressed data length exceedsbody_size_limit.Checklist