🛡️ Sentinel: [CRITICAL] Fix CSV formula injection via NUL bytes

[seonghobae]

🚨 Severity: CRITICAL
💡 Vulnerability: The existing CSV formula injection mitigation was vulnerable to bypasses using NUL bytes (\x00). Spreadsheets like Excel will often ignore these bytes and still evaluate the subsequent payload (e.g. \x00=cmd).
🎯 Impact: An attacker could exploit this to achieve arbitrary formula injection/remote code execution when a victim opens a crafted, exported CSV file.
🔧 Fix: Expanded the mitigation regex in apps/desktop/src/lib/export.ts to include \x00. Used // eslint-disable-next-line no-control-regex to permit the deliberate control character usage.
✅ Verification: Verified by updating tests in apps/desktop/src/lib/export.test.ts to assert that NUL bytes are properly sanitized and running npm run test and ./scripts/harness/quickcheck.sh.

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PR created automatically by Jules for task 2418472041287486662 started by @seonghobae

Summary by CodeRabbit

• 버그 수정

  • CSV 내보내기 시 NUL 바이트로 숨겨진 수식 주입 우회 가능성을 차단했습니다.
  • NUL 바이트가 포함된 위험한 입력에도 안전한 접두 처리가 적용됩니다.

• 테스트

  • NUL 바이트가 포함된 CSV 수식 주입 방지 검증을 추가했습니다.

[google-labs-jules]

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Team

Run ID: 6bfe1e07-0564-4d06-bedd-c343646d2977

📥 Commits

Reviewing files that changed from the base of the PR and between 314ddea and 5347617.

📒 Files selected for processing (3)

• .jules/sentinel.md
• apps/desktop/src/lib/export.test.ts
• apps/desktop/src/lib/export.ts

Included review availability: Your plan provides up to 1 included review per hour; 0 remain after this review.

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📝 Walkthrough

Walkthrough

CSV 수식 주입 방어 정규식에 NUL 바이트가 추가되었습니다. NUL 바이트가 포함된 위험 입력의 이스케이프 테스트와 대응 지침도 추가되었습니다.

Changes

CSV 수식 주입 방어

Layer / File(s)	Summary
NUL 바이트 수식 접두사 차단 apps/desktop/src/lib/export.ts, apps/desktop/src/lib/export.test.ts, .jules/sentinel.md	escapeCsvField가 NUL 바이트로 시작하거나 공백과 NUL 바이트가 결합된 위험 입력에 작은따옴표를 추가합니다. 관련 테스트와 CSV 처리 지침을 추가했습니다.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to 53476

CSV exports now prefix NUL-padded formula-like values with a protective quote, preventing this formula-injection bypass. The changed behavior is covered by targeted tests and presents no remaining merge-blocking risk.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	제목은 NUL 바이트를 이용한 CSV 수식 주입 우회 방지라는 주요 변경 사항을 정확하게 설명합니다. 이모지와 우선순위 표기가 포함되었지만 의미 전달을 방해하지 않습니다.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 2 files. (1 skipped: 1 …
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-csv-injection-2418472041287486662

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[seonghobae]

Succession receipt: #1177 (f9875aed9403d6372297d107f78b2f7a0807ec10) fully carries this PR's valid NUL-byte source/test delta on a clean protected-base descendant and strengthens it to the already-established canonical boundary: repeated NUL/NUL-only, all leading C0 controls, and full-width formula operators are covered by executable regressions and production policy. The CRITICAL/remote-code-execution wording is intentionally not inherited because repository evidence only supports a bounded defense-in-depth parser-disagreement claim; spreadsheet interpretation is consumer-dependent. No #1175 check/review/status evidence transfers. Closing unmerged is complete semantic succession, not abandonment.

[google-labs-jules]

Succession receipt: #1177 (f9875aed9403d6372297d107f78b2f7a0807ec10) fully carries this PR's valid NUL-byte source/test delta on a clean protected-base descendant and strengthens it to the already-established canonical boundary: repeated NUL/NUL-only, all leading C0 controls, and full-width formula operators are covered by executable regressions and production policy. The CRITICAL/remote-code-execution wording is intentionally not inherited because repository evidence only supports a bounded defense-in-depth parser-disagreement claim; spreadsheet interpretation is consumer-dependent. No #1175 check/review/status evidence transfers. Closing unmerged is complete semantic succession, not abandonment.

Understood. Acknowledging that this work is now obsolete and superseded by PR #1177, which provides a more comprehensive fix. Stopping work on this task.