Reject truncated percent-encoding in RFC2231Utility.decodeText#477
Merged
Conversation
There was a problem hiding this comment.
Pull request overview
This PR tightens RFC 5987/RFC 2231 decoding in RFC2231Utility.decodeText by rejecting truncated percent-escape sequences (e.g., trailing % or %3), aligning behavior with other malformed-input handling paths and preventing silent truncation of decoded header parameter values.
Changes:
- Update
RFC2231Utility.fromHexto throwIllegalArgumentExceptionwhen a%escape is truncated (fewer than two following characters). - Add unit tests asserting truncated percent-escapes are rejected.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| src/main/java/org/apache/commons/fileupload/RFC2231Utility.java | Rejects truncated percent-encoding by throwing IllegalArgumentException instead of silently dropping the trailing escape. |
| src/test/java/org/apache/commons/fileupload/RFC2231UtilityTestCase.java | Adds regression tests for truncated % escapes (% and %3). |
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
garydgregory
added a commit
that referenced
this pull request
Jul 13, 2026
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Port of #475 to
1.x, as requested there. Same change as merged onmaster, adapted toRFC2231Utility.Repro:
RFC2231Utility.decodeText("UTF-8''report%3")(a truncated RFC 5987 percent escape, reachable viafilename*).Expected: rejected, the same as
%GGor a non-ASCII byte already are.Actual: returns
report;fromHextreats a%with fewer than two following characters as end-of-input and drops the truncated escape.Fix: throw
IllegalArgumentException, matching the other malformed-input paths infromHex. Covered by a new case inRFC2231UtilityTestCase; full suite passes on1.x(86 tests, 0 failures).