🧹 fix: Sanitize Artifact Filenames in Code Execution Output#12222
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Pull request overview
This PR hardens file handling against path traversal by adding filename sanitization/containment checks and introducing regression tests around unsafe filenames.
Changes:
- Add a local filesystem path containment check before writing buffers to disk.
- Sanitize code-artifact filenames before saving code execution outputs.
- Add Jest tests covering traversal scenarios for both local buffer saving and code output processing.
Reviewed changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
| api/server/services/Files/Local/crud.js | Adds a directory containment check before writing a buffer to the local filesystem. |
| api/server/services/Files/Local/tests/crud-traversal.spec.js | Adds tests validating traversal rejection and normal filename acceptance for saveLocalBuffer. |
| api/server/services/Files/Code/process.js | Sanitizes code artifact names via sanitizeFilename before persisting outputs. |
| api/server/services/Files/Code/tests/process-traversal.spec.js | Adds tests asserting sanitizeFilename usage and that traversal inputs don’t reach storage unsanitized. |
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danny-avila
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… original filename - Added a mock implementation for the `sanitizeFilename` function in the `process.spec.js` test file to return the original filename, ensuring that tests can run without altering the filename during the testing process.
…dd security logging - Replace startsWith with path.relative pattern in saveLocalBuffer, consistent with deleteLocalFile and getLocalFileStream in the same file - Hoist sanitizeFilename call before the image/non-image branch so both code paths store the sanitized name in MongoDB - Log a warning when sanitizeFilename mutates a filename (potential traversal) - Log a specific warning when saveLocalBuffer throws a traversal error, so security events are distinguishable from generic network errors in the catch
- Remove partial sanitizeFilename reimplementation from process-traversal tests; use controlled mock returns to verify processCodeOutput wiring instead - Add test for image branch sanitization - Use mkdtempSync for test isolation in crud-traversal to avoid parallel worker collisions - Add prefix-collision bypass test case (../user10/evil vs user1 directory)
Pre-existing startsWith check without path separator had the same class of prefix-collision vulnerability fixed in saveLocalBuffer.
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jcbartle
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May 11, 2026
…ila#12222) * fix: sanitize artifact filenames to prevent path traversal in code output * test: Mock sanitizeFilename function in process.spec.js to return the original filename - Added a mock implementation for the `sanitizeFilename` function in the `process.spec.js` test file to return the original filename, ensuring that tests can run without altering the filename during the testing process. * fix: use path.relative for traversal check, sanitize all filenames, add security logging - Replace startsWith with path.relative pattern in saveLocalBuffer, consistent with deleteLocalFile and getLocalFileStream in the same file - Hoist sanitizeFilename call before the image/non-image branch so both code paths store the sanitized name in MongoDB - Log a warning when sanitizeFilename mutates a filename (potential traversal) - Log a specific warning when saveLocalBuffer throws a traversal error, so security events are distinguishable from generic network errors in the catch * test: improve traversal test coverage and remove mock reimplementation - Remove partial sanitizeFilename reimplementation from process-traversal tests; use controlled mock returns to verify processCodeOutput wiring instead - Add test for image branch sanitization - Use mkdtempSync for test isolation in crud-traversal to avoid parallel worker collisions - Add prefix-collision bypass test case (../user10/evil vs user1 directory) * fix: use path.relative in isValidPath to prevent prefix-collision bypass Pre-existing startsWith check without path separator had the same class of prefix-collision vulnerability fixed in saveLocalBuffer.
ThomasVuNguyen
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Jul 15, 2026
…ila#12222) * fix: sanitize artifact filenames to prevent path traversal in code output * test: Mock sanitizeFilename function in process.spec.js to return the original filename - Added a mock implementation for the `sanitizeFilename` function in the `process.spec.js` test file to return the original filename, ensuring that tests can run without altering the filename during the testing process. * fix: use path.relative for traversal check, sanitize all filenames, add security logging - Replace startsWith with path.relative pattern in saveLocalBuffer, consistent with deleteLocalFile and getLocalFileStream in the same file - Hoist sanitizeFilename call before the image/non-image branch so both code paths store the sanitized name in MongoDB - Log a warning when sanitizeFilename mutates a filename (potential traversal) - Log a specific warning when saveLocalBuffer throws a traversal error, so security events are distinguishable from generic network errors in the catch * test: improve traversal test coverage and remove mock reimplementation - Remove partial sanitizeFilename reimplementation from process-traversal tests; use controlled mock returns to verify processCodeOutput wiring instead - Add test for image branch sanitization - Use mkdtempSync for test isolation in crud-traversal to avoid parallel worker collisions - Add prefix-collision bypass test case (../user10/evil vs user1 directory) * fix: use path.relative in isValidPath to prevent prefix-collision bypass Pre-existing startsWith check without path separator had the same class of prefix-collision vulnerability fixed in saveLocalBuffer.
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