🛡️ Sentinel: [MEDIUM] 텍스트 Form 필드에 길이 제한을 추가하여 DoS 공격 방지

[seonghobae]

🚨 Severity: MEDIUM
💡 Vulnerability: FastAPI에서 길이 제한이 없는 Form 필드는 메모리 고갈을 통한 DoS 공격에 악용될 수 있습니다. (python-multipart는 Form 필드 전체를 메모리에 적재합니다)
🎯 Impact: 악의적인 사용자가 거대한 문자열을 전송하여 서버 메모리를 고갈시키고 서비스를 중단시킬 수 있습니다.
🔧 Fix: language 및 mode Form 필드에 max_length=50 속성을 추가하여 입력 크기를 제한했습니다.
✅ Verification: 테스트를 추가하여 비정상적으로 긴 입력이 422 에러와 함께 거부되는 것을 확인했습니다. 테스트 커버리지를 100%로 유지했습니다.

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PR created automatically by Jules for task 564629990633410586 started by @seonghobae

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[google-labs-jules]

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[coderabbitai]

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[devin-ai-integration]

Note

This report is out of date. Scroll down for Devin Review's latest report on this PR.

Devin Review found 3 potential issues.

[devin-ai-integration]

🟥 폼 제한 전 메모리 고갈

max_length는 multipart 파싱이 끝난 뒤 검증됩니다. 요청 하나가 제한 밖의 추가 필드 1,000개로 약 1GiB를 점유할 수 있습니다.

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[devin-ai-integration]

Devin Review found 1 new potential issue.

[devin-ai-integration]

📝 Info: 환경 제거로 테스트 의미는 바뀌지 않음

app은 함수 실행 전에 생성되므로 삭제된 setenv는 원래 적용되지 않았다. 동일한 환경값은 conftest.py가 테스트 수집 전에 설정한다.

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[seonghobae]

Verified-successor closure evidence from fresh live refs:

• predecessor: #752@351101c055df52568f2aa55c5f442efdad604794
• canonical successor: #787@0877c638dd7f97df888a337b9b43f679a7ad5604
• protected target: develop@e06b1f3fb10903569124af011da213951e6e2473

#752's valid product contract is fully carried forward: both language and mode use Form(max_length=50), and #787 has focused regressions requiring 51-character values for both fields to return 422. #787 additionally owns the separate pre-multipart request-body admission boundary, so the field validation is not used as evidence that bytes already consumed by the multipart parser were bounded.

The generated .jules/sentinel.md appendix from #752 is intentionally not inherited. Its blanket rule that every string Form() must use a tight max length and its claim that this alone prevents multipart memory exhaustion over-generalize a product-local validation decision and conflate post-parse value validation with pre-parser resource admission.

No unique valid production/test/fixture/contract delta remains on #752 after that succession. Closing therefore uses complete semantic/test succession plus explicit rejection of invalid generated doctrine; it is not a simple PR-count close. #787 remains Draft/non-terminal and must earn its own exact-head GREEN.

[google-labs-jules]

Verified-successor closure evidence from fresh live refs:

• predecessor: #752@351101c055df52568f2aa55c5f442efdad604794
• canonical successor: #787@0877c638dd7f97df888a337b9b43f679a7ad5604
• protected target: develop@e06b1f3fb10903569124af011da213951e6e2473

#752's valid product contract is fully carried forward: both language and mode use Form(max_length=50), and #787 has focused regressions requiring 51-character values for both fields to return 422. #787 additionally owns the separate pre-multipart request-body admission boundary, so the field validation is not used as evidence that bytes already consumed by the multipart parser were bounded.

The generated .jules/sentinel.md appendix from #752 is intentionally not inherited. Its blanket rule that every string Form() must use a tight max length and its claim that this alone prevents multipart memory exhaustion over-generalize a product-local validation decision and conflate post-parse value validation with pre-parser resource admission.

No unique valid production/test/fixture/contract delta remains on #752 after that succession. Closing therefore uses complete semantic/test succession plus explicit rejection of invalid generated doctrine; it is not a simple PR-count close. #787 remains Draft/non-terminal and must earn its own exact-head GREEN.

Understood. Acknowledging that this work is now obsolete and stopping work on this task.