🛡️ Sentinel: [CRITICAL] Fix directory traversal vulnerability in static file serving#183
🛡️ Sentinel: [CRITICAL] Fix directory traversal vulnerability in static file serving#183Tuntii wants to merge 2 commits into
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This commit fixes a vulnerability where percent-encoded characters like `%2e%2e%2f` could bypass the simple string-based `sanitize_path` protection, potentially leading to Local File Inclusion (LFI). The fix: 1. Adds `percent-encoding` to properly decode requested paths. 2. Uses `tokio::fs::canonicalize()` on both the root directory and the requested file path. 3. Explicitly verifies that the resolved, canonicalized file path starts with the canonicalized root directory. This canonicalization check provides an iron-clad defense against all forms of directory traversal.
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Pull request overview
This PR hardens rustapi-core static file serving against directory traversal/LFI by decoding percent-encoded paths and enforcing a canonicalized “must be under root” boundary check before serving files.
Changes:
- Percent-decode the incoming relative path before sanitization in
StaticFile::serve. - Add canonicalization +
starts_withboundary enforcement inserve_file. - Add integration tests covering traversal attempts and encoded filenames; add
percent-encodingdependency.
Reviewed changes
Copilot reviewed 3 out of 4 changed files in this pull request and generated 5 comments.
| File | Description |
|---|---|
crates/rustapi-core/src/static_files.rs |
Adds percent-decoding and canonicalized root/file boundary verification to block traversal. |
crates/rustapi-core/tests/static_files_security_test.rs |
Adds traversal/LFI regression tests and a percent-encoded filename test. |
crates/rustapi-core/Cargo.toml |
Adds percent-encoding dependency. |
Cargo.lock |
Locks the new dependency. |
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| // Security check: ensure the resolved path is within the root directory | ||
| let canonical_root = match tokio::fs::canonicalize(&config.root).await { | ||
| Ok(root) => root, | ||
| Err(_) => return Err(ApiError::internal("Static file root directory not found")), | ||
| }; |
| assert!(res_encoded.is_err(), "Encoded traversal should be blocked"); | ||
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| // Double encoded | ||
| let relative_path_double = "%2e%2e%2f%2e%2e%2fetc%2fpasswd"; |
| let canonical_file = match tokio::fs::canonicalize(path).await { | ||
| Ok(file) => file, | ||
| Err(_) => return Err(ApiError::not_found("File not found")), | ||
| }; | ||
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| let config = serve_dir("/static", "./"); // root is crates/rustapi-core | ||
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| // We try to access something outside the root | ||
| let relative_path = "../../etc/passwd"; |
| let _ = std::fs::create_dir_all("./test_dir"); | ||
| let _ = File::create("./test_dir/file with spaces.txt"); | ||
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| let config = serve_dir("/static", "./test_dir"); |
This commit fixes a vulnerability where percent-encoded characters like `%2e%2e%2f` could bypass the simple string-based `sanitize_path` protection, potentially leading to Local File Inclusion (LFI). The fix: 1. Adds `percent-encoding` to properly decode requested paths. 2. Uses `tokio::fs::canonicalize().await` on both the root directory and the requested file path, maintaining async best practices. 3. Explicitly verifies that the resolved, canonicalized file path starts with the canonicalized root directory. This canonicalization check provides an iron-clad defense against all forms of directory traversal.
This PR secures the
StaticFileserving module inrustapi-coreagainst directory traversal and Local File Inclusion (LFI) vulnerabilities.Vulnerability
Previously, the
sanitize_pathfunction attempted to prevent directory traversal by stripping literal..segments. However, this could be bypassed using URL percent-encoding (e.g.,%2e%2e%2ffor../), as the path was not decoded before sanitization. Depending on the routing layer configuration, this could allow attackers to access files outside the intended root directory.Fix
This PR implements a robust defense-in-depth approach:
percent_encoding::percent_decode_strbefore any processing occurs.tokio::fs::canonicalizeon both the static file root directory and the requested file path.starts_withthe canonicalized root directory. If it doesn't, it returns a 404 Not Found. This completely eliminates the possibility of serving files outside the intended directory tree, regardless of symlinks or complex encoding tricks.New tests have been added to verify that standard and percent-encoded traversal attempts are properly blocked.
PR created automatically by Jules for task 17484869118111250650 started by @Tuntii