security: confine file commands and validate deep-link targets#57
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read_file/write_file/delete_file were unconstrained filesystem primitives reachable from the frontend and — via the quill:// deep link — indirectly from any web page. A crafted path could read /etc/passwd or overwrite an arbitrary file. - ensure_allowed_path confines the three commands to Markdown documents and their .comments.json sidecars, the only paths any legitimate caller uses. The native open/save dialogs already restrict the user to .md, so no real capability is lost. - parse_quill_open now resolves the decoded path and accepts it only if it canonicalizes to an existing regular .md/.markdown file (symlink re-checked), so a hostile quill://open?file=/etc/passwd can no longer coax Quill into touching arbitrary files. Adds unit coverage for the path policy, the confined commands, and deep-link target validation (existing file, missing file, non-Markdown target, directory-with-.md-suffix, wrong host). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Documents Quill's security posture for a reviewing engineer: the threat model (deep link as the one attacker-influenced entry point; deserialized data trusted more than rendered data), the four merged hardening measures (#57 path confinement + deep-link validation, #58 annotation sanitization, #59 URL scheme allowlists, #60 binary-resolution hardening), and the two deliberate non-fixes left in place with rationale (asset-protocol $HOME/** scope, remote-image beacon). Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
This was referenced Jun 14, 2026
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What
Hardens the Tauri file-IO boundary, the most attacker-exposed surface in the app.
read_file/write_file/delete_filewere unconstrained filesystem primitives. They're reachable from the frontend and — through thequill://open?file=…deep link, which any web page can fire — indirectly from a hostile origin. A crafted path could read/etc/passwdor overwrite an arbitrary file.Changes
ensure_allowed_pathconfines the three commands to Markdown documents and their.comments.jsonsidecars — the only paths any legitimate caller ever uses. The native open/save dialogs already restrict the user to.md, so no real capability is lost.parse_quill_opennow resolves the decoded path and accepts it only if it canonicalizes to an existing regular.md/.markdownfile (symlink target re-checked). A hostilequill://open?file=/etc/passwdcan no longer reachread_fileat all.Tests
Five new unit tests (35 Rust tests total, all green): path policy accept/reject, the confined commands refusing disallowed paths, and deep-link validation across existing file / missing file / non-Markdown target / directory-with-
.md-suffix / wrong host.Full local bar green:
cargo fmt --check,cargo clippy -D warnings,cargo test, and vitest (231) via the pre-commit hook.🤖 Generated with Claude Code