4 files changed, 33 insertions, 11 deletions
diff --git a/src/server/activitypub/featured.ts b/src/server/activitypub/featured.ts
index f400cc416f..12613b3ecf 100644
--- a/src/server/activitypub/featured.ts
+++ b/src/server/activitypub/featured.ts
@@ -1,4 +1,4 @@
-import * as mongo from 'mongodb';
+import { ObjectID } from 'mongodb';
 import * as Router from 'koa-router';
 import config from '../../config';
 import User from '../../models/user';
@@ -9,7 +9,12 @@ import Note from '../../models/note';
 import renderNote from '../../remote/activitypub/renderer/note';
 
 export default async (ctx: Router.IRouterContext) => {
-	const userId = new mongo.ObjectID(ctx.params.user);
+	if (!ObjectID.isValid(ctx.params.user)) {
+		ctx.status = 404;
+		return;
+	}
+
+	const userId = new ObjectID(ctx.params.user);
 
 	// Verify user
 	const user = await User.findOne({
@@ -24,7 +29,7 @@ export default async (ctx: Router.IRouterContext) => {
 
 	const pinnedNoteIds = user.pinnedNoteIds || [];
 
-	const pinnedNotes = await Promise.all(pinnedNoteIds.map(id => Note.findOne({ _id: id })));
+	const pinnedNotes = await Promise.all(pinnedNoteIds.filter(ObjectID.isValid).map(id => Note.findOne({ _id: id })));
 
 	const renderedNotes = await Promise.all(pinnedNotes.map(note => renderNote(note)));
 
diff --git a/src/server/activitypub/followers.ts b/src/server/activitypub/followers.ts
index 5c809424cc..9c28c98cd8 100644
--- a/src/server/activitypub/followers.ts
+++ b/src/server/activitypub/followers.ts
@@ -1,4 +1,4 @@
-import * as mongo from 'mongodb';
+import { ObjectID } from 'mongodb';
 import * as Router from 'koa-router';
 import config from '../../config';
 import $ from 'cafy'; import ID, { transform } from '../../misc/cafy-id';
@@ -11,7 +11,12 @@ import renderFollowUser from '../../remote/activitypub/renderer/follow-user';
 import { setResponseType } from '../activitypub';
 
 export default async (ctx: Router.IRouterContext) => {
-	const userId = new mongo.ObjectID(ctx.params.user);
+	if (!ObjectID.isValid(ctx.params.user)) {
+		ctx.status = 404;
+		return;
+	}
+
+	const userId = new ObjectID(ctx.params.user);
 
 	// Get 'cursor' parameter
 	const [cursor = null, cursorErr] = $.type(ID).optional.get(ctx.request.query.cursor);
diff --git a/src/server/activitypub/following.ts b/src/server/activitypub/following.ts
index a46bb9c7ff..97245245ad 100644
--- a/src/server/activitypub/following.ts
+++ b/src/server/activitypub/following.ts
@@ -1,7 +1,8 @@
-import * as mongo from 'mongodb';
+import { ObjectID } from 'mongodb';
 import * as Router from 'koa-router';
 import config from '../../config';
-import $ from 'cafy'; import ID, { transform } from '../../misc/cafy-id';
+import $ from 'cafy';
+import ID, { transform } from '../../misc/cafy-id';
 import User from '../../models/user';
 import Following from '../../models/following';
 import pack from '../../remote/activitypub/renderer';
@@ -11,7 +12,12 @@ import renderFollowUser from '../../remote/activitypub/renderer/follow-user';
 import { setResponseType } from '../activitypub';
 
 export default async (ctx: Router.IRouterContext) => {
-	const userId = new mongo.ObjectID(ctx.params.user);
+	if (!ObjectID.isValid(ctx.params.user)) {
+		ctx.status = 404;
+		return;
+	}
+
+	const userId = new ObjectID(ctx.params.user);
 
 	// Get 'cursor' parameter
 	const [cursor = null, cursorErr] = $.type(ID).optional.get(ctx.request.query.cursor);
diff --git a/src/server/activitypub/outbox.ts b/src/server/activitypub/outbox.ts
index 6b917ef843..c35298e3a8 100644
--- a/src/server/activitypub/outbox.ts
+++ b/src/server/activitypub/outbox.ts
@@ -1,7 +1,8 @@
-import * as mongo from 'mongodb';
+import { ObjectID } from 'mongodb';
 import * as Router from 'koa-router';
 import config from '../../config';
-import $ from 'cafy'; import ID, { transform } from '../../misc/cafy-id';
+import $ from 'cafy';
+import ID, { transform } from '../../misc/cafy-id';
 import User from '../../models/user';
 import pack from '../../remote/activitypub/renderer';
 import renderOrderedCollection from '../../remote/activitypub/renderer/ordered-collection';
@@ -15,7 +16,12 @@ import renderAnnounce from '../../remote/activitypub/renderer/announce';
 import { countIf } from '../../prelude/array';
 
 export default async (ctx: Router.IRouterContext) => {
-	const userId = new mongo.ObjectID(ctx.params.user);
+	if (!ObjectID.isValid(ctx.params.user)) {
+		ctx.status = 404;
+		return;
+	}
+
+	const userId = new ObjectID(ctx.params.user);
 
 	// Get 'sinceId' parameter
 	const [sinceId, sinceIdErr] = $.type(ID).optional.get(ctx.request.query.since_id);