fix(mcp): pass SSRF-guarded fetch into OAuth callback token exchange

apps/sim/app/api/mcp/oauth/callback/route.test.ts

@@ -0,0 +1,85 @@
+/**
+ * @vitest-environment node
+ */
+import {
+ authMockFns,
+ dbChainMock,
+ dbChainMockFns,
+ mcpOauthMock,
+ mcpOauthMockFns,
+ resetDbChainMock,
+ schemaMock,
+} from '@sim/testing'
+import { NextRequest } from 'next/server'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const { mockMcpAuth, mockCreateSsrfGuardedMcpFetch, mockGuardedFetch, mockDiscoverServerTools } =
+ vi.hoisted(() => ({
+ mockMcpAuth: vi.fn(),
+ mockCreateSsrfGuardedMcpFetch: vi.fn(),
+ mockGuardedFetch: vi.fn(),
+ mockDiscoverServerTools: vi.fn(),
+ }))
+
+vi.mock('@sim/db', () => dbChainMock)
+vi.mock('@sim/db/schema', () => schemaMock)
+vi.mock('drizzle-orm', () => ({
+ and: vi.fn(),
+ eq: vi.fn(),
+ isNull: vi.fn(),
+}))
+vi.mock('@modelcontextprotocol/sdk/client/auth.js', () => ({
+ auth: mockMcpAuth,
+}))
+vi.mock('@/lib/mcp/oauth', () => mcpOauthMock)
+vi.mock('@/lib/mcp/pinned-fetch', () => ({
+ createSsrfGuardedMcpFetch: mockCreateSsrfGuardedMcpFetch,
+}))
+vi.mock('@/lib/mcp/service', () => ({
+ mcpService: { discoverServerTools: mockDiscoverServerTools },
+}))
+
+import { GET } from './route'
+
+describe('MCP OAuth callback route', () => {
+ beforeEach(() => {
+ vi.clearAllMocks()
+ resetDbChainMock()
+ mockCreateSsrfGuardedMcpFetch.mockReturnValue(mockGuardedFetch)
+ authMockFns.mockGetSession.mockResolvedValue({ user: { id: 'user-1' } })
+ mcpOauthMockFns.mockLoadOauthRowByState.mockResolvedValue({
+ id: 'oauth-row-1',
+ mcpServerId: 'server-1',
+ userId: 'user-1',
+ workspaceId: 'workspace-1',
+ })
+ dbChainMockFns.limit.mockResolvedValue([
+ {
+ id: 'server-1',
+ url: 'https://mcp.example.com/mcp',
+ workspaceId: 'workspace-1',
+ },
+ ])
+ mcpOauthMockFns.mockLoadPreregisteredClient.mockResolvedValue(undefined)
+ mockMcpAuth.mockResolvedValue('AUTHORIZED')
+ mockDiscoverServerTools.mockResolvedValue(undefined)
+ })
+
+ it('performs the token exchange through the SSRF-guarded fetch', async () => {
+ const request = new NextRequest(
+ 'http://localhost:3000/api/mcp/oauth/callback?state=state-1&code=auth-code-1'
+ )
+
+ await GET(request)
+
+ expect(mockCreateSsrfGuardedMcpFetch).toHaveBeenCalledTimes(1)
+ expect(mockMcpAuth).toHaveBeenCalledWith(
+ expect.anything(),
+ expect.objectContaining({
+ serverUrl: 'https://mcp.example.com/mcp',
+ authorizationCode: 'auth-code-1',
+ fetchFn: mockGuardedFetch,
+ })
+ )
+ })
+})

apps/sim/app/api/mcp/oauth/callback/route.ts

@@ -19,6 +19,7 @@ import {
  type McpOauthCallbackReason,
  SimMcpOauthProvider,
 } from '@/lib/mcp/oauth'
+import { createSsrfGuardedMcpFetch } from '@/lib/mcp/pinned-fetch'
 import { mcpService } from '@/lib/mcp/service'
 
 const logger = createLogger('McpOauthCallbackAPI')
@@ -149,6 +150,7 @@ export const GET = withRouteHandler(async (request: NextRequest) => {
  result = await mcpAuth(provider, {
  serverUrl: server.url,
  authorizationCode: code,
+ fetchFn: createSsrfGuardedMcpFetch(),
  })
  } catch (e) {
  logger.error('Token exchange failed during MCP OAuth callback', e)