🛡️ Sentinel: [HIGH] Fix SSRF bypass via empty hostname

[seonghobae]

Verified successor

This PR is closed without merge because its valid runtime/test/documentation delta is fully inherited by the existing canonical repair lane #1068 rather than discarded.

Successor exact head at consolidation: ed65fddafe40b9982d960425b56744b47cb5aa81 on sentinel/fix-empty-hostname-ssrf-14253541902387870366.

Inherited evidence:

• both production _is_safe_url implementations reject a missing hostname before IP/DNS validation;
• both implementations additionally fail closed when DNS cannot establish a public destination, which is stricter than this PR's fail-open predecessor behavior;
• 🛡️ Sentinel: [HIGH] Fix empty hostname SSRF bypass #1068 already covers http:// and http://user@ for control-plane and CLI; descendant ed65fdda... adds the remaining http://user:pass@ credential-only authority fixture from this PR so the test evidence is not lost;
• 🛡️ Sentinel: [HIGH] Fix empty hostname SSRF bypass #1068's security journal already records the empty-host failure mode and prevention without relying on this PR's stronger, unverified claim that a later HTTP layer would necessarily reinterpret an empty host as a local address;
• 🛡️ Sentinel: [HIGH] Fix empty hostname SSRF bypass #1068 also owns the packaged CWE-918 detector contract and deterministic resolver-failure evidence for the same defect class.

No semantic/test/fixture/contract evidence from this PR is being dropped. #1068 remains Draft and still requires exact-head hosted gates and independent review before promotion; this closure is consolidation, not a substitute for those gates.

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Team

Run ID: 5fcac245-aa64-4be6-b71d-1bfd0f502565

📥 Commits

Reviewing files that changed from the base of the PR and between e71d37e and 95a34af.

📒 Files selected for processing (4)

• .jules/sentinel.md
• appguardrail_core/controlplane.py
• scanner/cli/appguardrail.py
• tests/test_ssrf_protection.py

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

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📝 Walkthrough

Walkthrough

두 _is_safe_url 구현이 빈 호스트명을 DNS 해석 전에 거부합니다. 회귀 테스트는 호스트가 없는 URL 세 가지를 검증합니다. 보안 학습 로그는 원인과 예방책을 기록합니다.

Changes

빈 호스트 SSRF 차단

Layer / File(s)	Summary
빈 호스트명 조기 거부 .jules/sentinel.md, appguardrail_core/controlplane.py, scanner/cli/appguardrail.py	Controlplane과 CLI의 _is_safe_url이 빈 호스트명을 발견하면 False를 반환합니다. 보안 학습 로그에 SSRF 우회 원인과 예방책을 추가했습니다.
빈 호스트 회귀 검증 tests/test_ssrf_protection.py	http://, http://user@, http://user:pass@를 두 _is_safe_url 구현이 거부하는지 검증합니다.

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

Merge Risk: ⚪ Minimal · up to 95a34

Both URL safety checks now reject empty hostnames before DNS resolution, with regression coverage for hostless URL forms. No current merge-blocking risk remains.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 6 functions across 3 files. (1 skipped: 1 …	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	제목은 빈 호스트명을 이용한 SSRF 우회 수정이라는 주요 변경 사항을 정확하고 구체적으로 요약합니다.
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.

Full details: Docstring Coverage

Explanation

Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 6 functions across 3 files. (1 skipped: 1 unsupported.)

• Fix all pre-merge checks with AI

✨ Finishing Touches 💡 1

📝 Generate docstrings 💡

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/ssrf-empty-host-6165286561452253538

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