fix: respond with 200 to HEAD requests for non-prerendered pages as well

.changeset/tricky-toes-drum.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes a bug where HEAD requests for non-prerendered pages were incorrectly rejected with 403 FORBIDDEN

packages/astro/src/core/app/middlewares.ts

@@ -13,6 +13,9 @@ const FORM_CONTENT_TYPES = [
 	'text/plain',
 ];
 
+// Note: TRACE is unsupported by undici/Node.js
+const SAFE_METHODS = ['GET', 'HEAD', 'OPTIONS'];
+
 /**
  * Returns a middleware function in charge to check the `origin` header.
  *
@@ -25,26 +28,22 @@ export function createOriginCheckMiddleware(): MiddlewareHandler {
 		if (isPrerendered) {
 			return next();
 		}
-		if (request.method === 'GET') {
+		// Safe methods don't require origin check
+		if (SAFE_METHODS.includes(request.method)) {
 			return next();
 		}
-		const sameOrigin =
-			(request.method === 'POST' ||
-				request.method === 'PUT' ||
-				request.method === 'PATCH' ||
-				request.method === 'DELETE') &&
-			request.headers.get('origin') === url.origin;
+		const isSameOrigin = request.headers.get('origin') === url.origin;
 
 		const hasContentType = request.headers.has('content-type');
 		if (hasContentType) {
 			const formLikeHeader = hasFormLikeHeader(request.headers.get('content-type'));
-			if (formLikeHeader && !sameOrigin) {
+			if (formLikeHeader && !isSameOrigin) {
 				return new Response(`Cross-site ${request.method} form submissions are forbidden`, {
 					status: 403,
 				});
 			}
 		} else {
-			if (!sameOrigin) {
+			if (!isSameOrigin) {
 				return new Response(`Cross-site ${request.method} form submissions are forbidden`, {
 					status: 403,
 				});

packages/astro/test/csrf-protection.test.js

@@ -176,6 +176,57 @@ describe('CSRF origin check', () => {
 		});
 	});
 
+	it("return a 200 when the origin doesn't match but calling HEAD", async () => {
+		let request;
+		let response;
+		request = new Request('http://example.com/api/', {
+			headers: { origin: 'http://loreum.com', 'content-type': 'multipart/form-data' },
+			method: 'HEAD',
+		});
+		response = await app.render(request);
+		assert.equal(response.status, 200);
+
+		request = new Request('http://example.com/api/', {
+			headers: { origin: 'http://loreum.com', 'content-type': 'application/x-www-form-urlencoded' },
+			method: 'HEAD',
+		});
+		response = await app.render(request);
+		assert.equal(response.status, 200);
+
+		request = new Request('http://example.com/api/', {
+			headers: { origin: 'http://loreum.com', 'content-type': 'text/plain' },
+			method: 'HEAD',
+		});
+		response = await app.render(request);
+		assert.equal(response.status, 200);
+	});
+
+	it("return a 200 when the origin doesn't match but calling OPTIONS", async () => {
+		let request;
+		let response;
+		request = new Request('http://example.com/api/', {
+			headers: { origin: 'http://loreum.com', 'content-type': 'multipart/form-data' },
+			method: 'OPTIONS',
+		});
+		response = await app.render(request);
+		assert.equal(response.status, 200);
+
+		request = new Request('http://example.com/api/', {
+			headers: { origin: 'http://loreum.com', 'content-type': 'application/x-www-form-urlencoded' },
+			method: 'OPTIONS',
+		});
+		response = await app.render(request);
+		assert.equal(response.status, 200);
+
+		request = new Request('http://example.com/api/', {
+			headers: { origin: 'http://loreum.com', 'content-type': 'text/plain' },
+			method: 'OPTIONS',
+		});
+		response = await app.render(request);
+		assert.equal(response.status, 200);
+	});
+
+
 	it('return 200 when calling POST/PUT/DELETE/PATCH with the correct origin', async () => {
 		let request;
 		let response;

packages/astro/test/fixtures/csrf-check-origin/src/pages/api.ts

@@ -27,3 +27,22 @@ export const PATCH = () => {
 		something: 'true',
 	});
 };
+
+export const HEAD = () => {
+	return Response.json({
+		something: 'true',
+	});
+};
+
+export const OPTIONS = () => {
+	return Response.json({
+		something: 'true',
+	});
+};
+
+
+export const TRACE = () => {
+	return Response.json({
+		something: 'true',
+	});
+};