🛡️ Sentinel: [CRITICAL] Fix SSRF vulnerability in bulk lookup API

[aicoder2009]

🚨 Severity: CRITICAL
💡 Vulnerability: The /api/lookup/bulk API endpoint utilized fetch appended with request.nextUrl.origin to proxy requests to internal endpoints (like URL, DOI, or ISBN lookups). Because request.nextUrl.origin is directly derived from the incoming user Host header, an attacker could manipulate it.
🎯 Impact: Manipulating the host header would cause the Next.js server to issue internal loopback requests (SSRF) to any arbitrary attacker-controlled domain or internal service accessible by the backend, leading to information disclosure and firewall bypass.
🔧 Fix: Refactored src/app/api/lookup/bulk/route.ts to directly import the internal API route handler modules (POST functions from ../url/route, ../doi/route, etc.) and invoke them directly with a newly constructed NextRequest synthetic request rather than performing a true network fetch(). The tests were also refactored to mock the internal handlers directly rather than global.fetch.
✅ Verification: Verified that tests pass via pnpm test. Code manually reviewed. No network requests are dispatched by the bulk lookup route anymore.

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PR created automatically by Jules for task 12824801053690868309 started by @aicoder2009

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Project	Deployment	Actions	Updated (UTC)
opencitation	Ready	Preview, Comment	May 27, 2026 6:35am

[Copilot]

Pull request overview

This PR removes a critical SSRF vector in the /api/lookup/bulk endpoint by eliminating internal loopback fetch() calls that previously relied on request.nextUrl.origin (derived from the user-controlled Host header). Instead, bulk lookups now directly invoke the internal Next.js route handlers for URL/DOI/ISBN lookups via synthetic NextRequest objects.

Changes:

• Replaced internal fetch(${request.nextUrl.origin}${apiEndpoint}) calls with direct invocation of imported route handlers (../url/route, ../doi/route, ../isbn/route).
• Updated bulk lookup tests to mock internal route handlers rather than mocking global.fetch.
• Documented the SSRF lesson/prevention pattern in .jules/sentinel.md.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated no comments.

File	Description
src/app/api/lookup/bulk/route.ts	Removes host-header-derived internal fetches and calls internal lookup handlers directly to prevent SSRF.
src/app/api/lookup/bulk/route.test.ts	Refactors tests to mock imported lookup handlers instead of global.fetch.
.jules/sentinel.md	Adds a write-up documenting the SSRF root cause and prevention approach for future reference.

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