Reject path traversal in filesystem storage#106
Merged
Conversation
andrew
added a commit
that referenced
this pull request
May 3, 2026
containsPathTraversal only checked literal ".." segments separated by forward slashes. Encoded forms like %2e%2e%2f or backslash separators would slip past if a caller ever passed a raw or Windows-style path. The check now URL-decodes the input and treats backslashes as separators before splitting. Go's stdlib already decodes r.URL.Path so the encoded case is mostly belt-and-braces for cache keys and other non-router inputs, but the storage layer guard from #106 makes this worth locking in with tests. Fixes #74
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
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Filesystem.fullPathjoined the request path ontofs.rootwithout verifying the result stayed inside the root, so a path containing../segments could read or write files outside the storage directory.fullPathnow cleans the joined path and returns an error (wrappingErrNotFound) if it does not equalfs.rootor sit beneathfs.root + separator.Store,Open,Exists,Delete,Sizeand the exportedFullPathpropagate the error.FullPathhad no callers outside the test file so its signature was changed to(string, error).Adds
TestFilesystemRejectsTraversalcovering../,../../anda/../../inputs againstOpenandStore.