Fix symlink escape in Gopher public file resolver#86
Closed
eouzoe wants to merge 1 commit into
Closed
Conversation
The userTree function confined selectors with path cleaning and HasPrefix checks, but called os.Stat/os.ReadFile on the unresolved path. A symlink created inside a member's public area pointing outside would pass the lexical checks and leak external content. Fix: resolve symlinks with filepath.EvalSymlinks after the path check and reject the request if the real path escapes the member's area. Adds TestSymlinkEscapeRefused to verify both rejection of external symlinks and acceptance of symlinks within the member area.
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Fixes #84
Problem
The Gopher resolver confined selectors with
filepath.CleanandHasPrefixchecks (line 308-311), but calledos.Stat/os.ReadFileon the unresolved path. A symlink created inside a member's public area pointing outside would pass the lexical checks and leak external content.Fix
Added a symlink escape guard using
filepath.EvalSymlinksafter the path check (line 314-320). If the resolved real path escapes the member's area, the request is refused with "forbidden".Test added
TestSymlinkEscapeRefusedingopher_test.goverifies: