Merge tag '1.3.20' into 1.4-maintenance (f5eb1df8) · Commits · sc07 / Fedify Patched

CHANGES.md

+22 −0

Original line number	Diff line number	Diff line
		@@ -8,6 +8,13 @@ Version 1.4.13

		To be released.

		- Fixed a critical authentication bypass vulnerability in the inbox handler
		that allowed unauthenticated attackers to impersonate any ActivityPub actor.
		The vulnerability occurred because activities were processed before
		verifying that the HTTP Signatures key belonged to the claimed actor.
		Now authentication verification is performed before activity processing to
		prevent actor impersonation attacks. [[CVE-2025-54888]]


		Version 1.4.12
		--------------
		@@ -258,6 +265,21 @@ Released on February 5, 2025.
		[#195]: https://github.com/fedify-dev/fedify/issues/195


		Version 1.3.20
		--------------

		Released on August 8, 2025.

		- Fixed a critical authentication bypass vulnerability in the inbox handler
		that allowed unauthenticated attackers to impersonate any ActivityPub actor.
		The vulnerability occurred because activities were processed before
		verifying that the HTTP Signatures key belonged to the claimed actor.
		Now authentication verification is performed before activity processing to
		prevent actor impersonation attacks. [[CVE-2025-54888]]

		[CVE-2025-54888]: https://github.com/fedify-dev/fedify/security/advisories/GHSA-6jcc-xgcr-q3h4


		Version 1.3.19
		--------------

src/deno.json

+1 −1

Original line number	Diff line number	Diff line
		@@ -38,7 +38,7 @@
		"@opentelemetry/semantic-conventions": "npm:@opentelemetry/semantic-conventions@^1.27.0",
		"@phensley/language-tag": "npm:@phensley/language-tag@^1.9.0",
		"@std/assert": "jsr:@std/assert@^0.226.0",
		"@std/async": "jsr:@std/async@^1.0.5",
		"@std/async": "jsr:@std/async@1.0.13",
		"@std/bytes": "jsr:@std/bytes@^1.0.2",
		"@std/collections": "jsr:@std/collections@^1.0.6",
		"@std/encoding": "jsr:@std/encoding@1.0.7",

src/federation/handler.test.ts

+81 −0

Original line number	Diff line number	Diff line
		@@ -35,6 +35,7 @@ import {
		respondWithObject,
		respondWithObjectIfAcceptable,
		} from "./handler.ts";
		import { InboxListenerSet } from "./inbox.ts";
		import { MemoryKvStore } from "./kv.ts";

		test("acceptsJsonLd()", () => {
		@@ -1350,6 +1351,86 @@ test("respondWithObject()", async () => {
		});
		});

		test("handleInbox() - authentication bypass vulnerability", async () => {
		// This test reproduces the authentication bypass vulnerability where
		// activities are processed before verifying the signing key belongs
		// to the claimed actor

		let processedActivity: Create \| undefined;
		const inboxListeners = new InboxListenerSet<void>();
		inboxListeners.add(Create, (_ctx, activity) => {
		// Track that the malicious activity was processed
		processedActivity = activity;
		});

		// Create malicious activity claiming to be from victim actor
		const maliciousActivity = new Create({
		id: new URL("https://attacker.example.com/activities/malicious"),
		actor: new URL("https://victim.example.com/users/alice"), // Impersonating victim
		object: new Note({
		id: new URL("https://attacker.example.com/notes/forged"),
		attribution: new URL("https://victim.example.com/users/alice"),
		content: "This is a forged message from the victim!",
		}),
		});

		// Sign request with attacker's key (not victim's key)
		const maliciousRequest = await signRequest(
		new Request("https://example.com/", {
		method: "POST",
		body: JSON.stringify(await maliciousActivity.toJsonLd()),
		}),
		rsaPrivateKey3, // Attacker's private key
		rsaPublicKey3.id!, // Attacker's public key ID
		);

		const maliciousContext = createRequestContext({
		request: maliciousRequest,
		url: new URL(maliciousRequest.url),
		data: undefined,
		documentLoader: mockDocumentLoader,
		});

		const actorDispatcher: ActorDispatcher<void> = (_ctx, identifier) => {
		if (identifier !== "someone") return null;
		return new Person({ name: "Someone" });
		};

		const response = await handleInbox(maliciousRequest, {
		recipient: "someone",
		context: maliciousContext,
		inboxContextFactory(_activity) {
		return createInboxContext({ ...maliciousContext, recipient: "someone" });
		},
		kv: new MemoryKvStore(),
		kvPrefixes: {
		activityIdempotence: ["_fedify", "activityIdempotence"],
		publicKey: ["_fedify", "publicKey"],
		},
		actorDispatcher,
		inboxListeners,
		onNotFound: () => new Response("Not found", { status: 404 }),
		signatureTimeWindow: { minutes: 5 },
		skipSignatureVerification: false,
		});

		// The vulnerability: Even though the response is 401 (unauthorized),
		// the malicious activity was already processed by routeActivity()
		assertEquals(response.status, 401);
		assertEquals(await response.text(), "The signer and the actor do not match.");

		assertEquals(
		processedActivity,
		undefined,
		`SECURITY VULNERABILITY: Malicious activity with mismatched signature was processed! ` +
		`Activity ID: ${processedActivity?.id?.href}, ` +
		`Claimed actor: ${processedActivity?.actorId?.href}`,
		);

		// If we reach here, the vulnerability is fixed - activities with mismatched
		// signatures are properly rejected before processing
		});

		test("respondWithObjectIfAcceptable", async () => {
		let request = new Request("https://example.com/", {
		headers: { Accept: "application/activity+json" },

src/federation/handler.ts

+14 −14

Original line number	Diff line number	Diff line
		@@ -649,20 +649,6 @@ async function handleInboxInternal<TContextData>(
		span.setAttribute("activitypub.activity.id", activity.id.href);
		}
		span.setAttribute("activitypub.activity.type", getTypeId(activity).href);
		const routeResult = await routeActivity({
		context: ctx,
		json,
		activity,
		recipient,
		inboxListeners,
		inboxContextFactory,
		inboxErrorHandler,
		kv,
		kvPrefixes,
		queue,
		span,
		tracerProvider,
		});
		if (
		httpSigKey != null && !await doesActorOwnKey(activity, httpSigKey, ctx)
		) {
		@@ -685,6 +671,20 @@ async function handleInboxInternal<TContextData>(
		headers: { "Content-Type": "text/plain; charset=utf-8" },
		});
		}
		const routeResult = await routeActivity({
		context: ctx,
		json,
		activity,
		recipient,
		inboxListeners,
		inboxContextFactory,
		inboxErrorHandler,
		kv,
		kvPrefixes,
		queue,
		span,
		tracerProvider,
		});
		if (routeResult === "alreadyProcessed") {
		return new Response(
		`Activity <${activity.id}> has already been processed.`,