Fix CWE-190 - DoS could happen with a specially crafted boundary parameter in a multipart request#445
Open
mathieucarbou wants to merge 2 commits into
Open
Fix CWE-190 - DoS could happen with a specially crafted boundary parameter in a multipart request#445mathieucarbou wants to merge 2 commits into
mathieucarbou wants to merge 2 commits into
Conversation
…meter in a multipart request
There was a problem hiding this comment.
Pull request overview
This PR addresses a security issue (CWE-190) in multipart request handling by constraining and hardening boundary parsing to prevent integer overflow / DoS scenarios during multipart body parsing.
Changes:
- Add validation to reject multipart boundaries that are empty or exceed RFC 2046’s 70-character limit.
- Change multipart boundary parsing state tracking (
_boundaryPosition) tosize_tand update a related loop to avoid overflow issues.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| src/WebRequest.cpp | Adds boundary length validation and updates multipart parsing loop indexing to use size_t. |
| src/ESPAsyncWebServer.h | Updates _boundaryPosition type to size_t to safely track boundary parsing progress. |
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Comment on lines
+487
to
+488
| _boundary = value.substring(bpos + 9); | ||
| int semi = _boundary.indexOf(';'); |
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Fix integer overflow.
See advisory: GHSA-4phx-fcj6-46r4
Tested with our UploadFlash example.