configurable cors settings

management/internals/server/boot.go

@@ -13,7 +13,6 @@ import (
 	"github.com/gorilla/mux"
 	grpcMiddleware "github.com/grpc-ecosystem/go-grpc-middleware/v2"
 	"github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/realip"
-	"github.com/rs/cors"
 	"github.com/rs/xid"
 	log "github.com/sirupsen/logrus"
 	"google.golang.org/grpc"
@@ -24,13 +23,13 @@ import (
 
 	"github.com/netbirdio/netbird/encryption"
 	"github.com/netbirdio/netbird/formatter/hook"
+	"github.com/netbirdio/netbird/management/internals/modules/agentnetwork"
 	"github.com/netbirdio/netbird/management/internals/modules/reverseproxy/accesslogs"
 	accesslogsmanager "github.com/netbirdio/netbird/management/internals/modules/reverseproxy/accesslogs/manager"
 	rpservice "github.com/netbirdio/netbird/management/internals/modules/reverseproxy/service"
 	nbgrpc "github.com/netbirdio/netbird/management/internals/shared/grpc"
 	"github.com/netbirdio/netbird/management/server/activity"
 	activitystore "github.com/netbirdio/netbird/management/server/activity/store"
-	"github.com/netbirdio/netbird/management/internals/modules/agentnetwork"
 	nbcache "github.com/netbirdio/netbird/management/server/cache"
 	nbContext "github.com/netbirdio/netbird/management/server/context"
 	nbhttp "github.com/netbirdio/netbird/management/server/http"
@@ -122,7 +121,7 @@ func (s *BaseServer) EventStore() activity.Store {
 
 func (s *BaseServer) APIHandler() http.Handler {
 	return Create(s, func() http.Handler {
-		httpAPIHandler, err := nbhttp.NewAPIHandler(context.Background(), s.Router(), s.AccountManager(), s.NetworksManager(), s.ResourcesManager(), s.RoutesManager(), s.GroupsManager(), s.GeoLocationManager(), s.AuthManager(), s.Metrics(), s.PermissionsManager(), s.SettingsManager(), s.ZonesManager(), s.RecordsManager(), s.NetworkMapController(), s.IdpManager(), s.ServiceManager(), s.ReverseProxyDomainManager(), s.AccessLogsManager(), s.ReverseProxyGRPCServer(), s.Config.ReverseProxy.TrustedHTTPProxies, s.RateLimiter(), s.IsValidChildAccount, s.AgentNetworkManager())
+		httpAPIHandler, err := nbhttp.NewAPIHandler(context.Background(), s.Router(), s.AccountManager(), s.NetworksManager(), s.ResourcesManager(), s.RoutesManager(), s.GroupsManager(), s.GeoLocationManager(), s.AuthManager(), s.Metrics(), s.PermissionsManager(), s.SettingsManager(), s.ZonesManager(), s.RecordsManager(), s.NetworkMapController(), s.IdpManager(), s.ServiceManager(), s.ReverseProxyDomainManager(), s.AccessLogsManager(), s.ReverseProxyGRPCServer(), s.Config.ReverseProxy.TrustedHTTPProxies, s.Config.HttpConfig.CORSAllowedOrigins, s.RateLimiter(), s.IsValidChildAccount, s.AgentNetworkManager())
 		if err != nil {
 			log.Fatalf("failed to create API handler: %v", err)
 		}
@@ -137,7 +136,7 @@ func (s *BaseServer) IDPHandler() http.Handler {
 	if !ok || embeddedIdP == nil {
 		return nil
 	}
-	return cors.AllowAll().Handler(embeddedIdP.Handler())
+	return nbhttp.CORSMiddleware(s.Config.HttpConfig.CORSAllowedOrigins).Handler(embeddedIdP.Handler())
 }
 
 func (s *BaseServer) Router() *mux.Router {

management/internals/server/config/config.go

@@ -125,6 +125,9 @@ type HttpServerConfig struct {
 	ExtraAuthAudience string
 	// AuthCallbackDomain contains the callback domain
 	AuthCallbackURL string
+	// CORSAllowedOrigins lists the browser origins allowed to read API responses,
+	// e.g. https://app.example.com. Any origin is allowed when left empty.
+	CORSAllowedOrigins []string
 }
 
 // Host represents a Netbird host (e.g. STUN, TURN, Signal)

management/server/http/cors_test.go

@@ -0,0 +1,55 @@
+package http
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func newCORSPreflight(origin string) *http.Request {
+	r := httptest.NewRequest(http.MethodOptions, "/api/peers", nil)
+	r.Header.Set("Origin", origin)
+	r.Header.Set("Access-Control-Request-Method", http.MethodPut)
+	r.Header.Set("Access-Control-Request-Headers", "authorization,content-type")
+	return r
+}
+
+func serveCORS(t *testing.T, allowedOrigins []string, r *http.Request) http.Header {
+	t.Helper()
+
+	w := httptest.NewRecorder()
+	CORSMiddleware(allowedOrigins).Handler(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	})).ServeHTTP(w, r)
+	return w.Header()
+}
+
+func TestCORSMiddlewareAllowsConfiguredOrigin(t *testing.T) {
+	headers := serveCORS(t, []string{"https://app.example.com"}, newCORSPreflight("https://app.example.com"))
+
+	assert.Equal(t, "https://app.example.com", headers.Get("Access-Control-Allow-Origin"))
+	assert.Contains(t, headers.Get("Vary"), "Origin")
+}
+
+func TestCORSMiddlewareRejectsUnknownOrigin(t *testing.T) {
+	headers := serveCORS(t, []string{"https://app.example.com"}, newCORSPreflight("https://evil.example.com"))
+
+	assert.Empty(t, headers.Get("Access-Control-Allow-Origin"))
+}
+
+func TestCORSMiddlewareNeverAllowsCredentials(t *testing.T) {
+	for _, allowedOrigins := range [][]string{nil, {"https://app.example.com"}} {
+		headers := serveCORS(t, allowedOrigins, newCORSPreflight("https://app.example.com"))
+
+		assert.Empty(t, headers.Get("Access-Control-Allow-Credentials"))
+		assert.Empty(t, headers.Get("Access-Control-Expose-Headers"))
+	}
+}
+
+func TestCORSMiddlewareWithoutConfigAllowsAnyOrigin(t *testing.T) {
+	headers := serveCORS(t, nil, newCORSPreflight("https://evil.example.com"))
+
+	assert.Equal(t, "*", headers.Get("Access-Control-Allow-Origin"))
+}

management/server/http/handler.go

@@ -60,8 +60,34 @@ import (
 	"github.com/netbirdio/netbird/management/server/telemetry"
 )
 
+// CORSMiddleware returns a CORS handler restricted to allowedOrigins. When none are
+// configured it falls back to allowing any origin, preserving the behaviour of
+// deployments that serve the dashboard and the API on different origins.
+// AllowCredentials stays false: the API authenticates via the Authorization header
+// only, so there are no ambient credentials for a foreign origin to abuse.
+func CORSMiddleware(allowedOrigins []string) *cors.Cors {
+	if len(allowedOrigins) == 0 {
+		log.Warn("no CORS allowed origins configured, allowing any origin; set HttpConfig.CORSAllowedOrigins to the dashboard origin to restrict it")
+		return cors.AllowAll()
+	}
+
+	return cors.New(cors.Options{
+		AllowedOrigins: allowedOrigins,
+		AllowedMethods: []string{
+			http.MethodHead,
+			http.MethodGet,
+			http.MethodPost,
+			http.MethodPut,
+			http.MethodPatch,
+			http.MethodDelete,
+		},
+		AllowedHeaders:   []string{"Authorization", "Content-Type"},
+		AllowCredentials: false,
+	})
+}
+
 // NewAPIHandler creates the Management service HTTP API handler registering all the available endpoints.
-func NewAPIHandler(ctx context.Context, router *mux.Router, accountManager account.Manager, networksManager nbnetworks.Manager, resourceManager resources.Manager, routerManager routers.Manager, groupsManager nbgroups.Manager, LocationManager geolocation.Geolocation, authManager auth.Manager, appMetrics telemetry.AppMetrics, permissionsManager permissions.Manager, settingsManager settings.Manager, zManager zones.Manager, rManager records.Manager, networkMapController network_map.Controller, idpManager idpmanager.Manager, serviceManager service.Manager, reverseProxyDomainManager *manager.Manager, reverseProxyAccessLogsManager accesslogs.Manager, proxyGRPCServer *nbgrpc.ProxyServiceServer, trustedHTTPProxies []netip.Prefix, rateLimiter *middleware.APIRateLimiter, isValidChildAccount middleware.IsValidChildAccountFunc, agentNetworkManager agentnetwork.Manager) (http.Handler, error) {
+func NewAPIHandler(ctx context.Context, router *mux.Router, accountManager account.Manager, networksManager nbnetworks.Manager, resourceManager resources.Manager, routerManager routers.Manager, groupsManager nbgroups.Manager, LocationManager geolocation.Geolocation, authManager auth.Manager, appMetrics telemetry.AppMetrics, permissionsManager permissions.Manager, settingsManager settings.Manager, zManager zones.Manager, rManager records.Manager, networkMapController network_map.Controller, idpManager idpmanager.Manager, serviceManager service.Manager, reverseProxyDomainManager *manager.Manager, reverseProxyAccessLogsManager accesslogs.Manager, proxyGRPCServer *nbgrpc.ProxyServiceServer, trustedHTTPProxies []netip.Prefix, corsAllowedOrigins []string, rateLimiter *middleware.APIRateLimiter, isValidChildAccount middleware.IsValidChildAccountFunc, agentNetworkManager agentnetwork.Manager) (http.Handler, error) {
 
 	// Register bypass paths for unauthenticated endpoints
 	if err := bypass.AddBypassPath("/api/instance"); err != nil {
@@ -98,7 +124,7 @@ func NewAPIHandler(ctx context.Context, router *mux.Router, accountManager accou
 		isValidChildAccount,
 	)
 
-	corsMiddleware := cors.AllowAll()
+	corsMiddleware := CORSMiddleware(corsAllowedOrigins)
 
 	metricsMiddleware := appMetrics.HTTPMiddleware()
 

management/server/http/testing/testing_tools/channel/channel.go

@@ -137,7 +137,7 @@ func BuildApiBlackBoxWithDBState(t testing_tools.TB, sqlFile string, expectedPee
 	zoneRecordsManager := recordsManager.NewManager(store, am, permissionsManager)
 
 	apiRouter := mux.NewRouter().PathPrefix("/api").Subrouter()
-	apiHandler, err := http2.NewAPIHandler(context.Background(), apiRouter, am, networksManager, resourcesManager, routersManager, groupsManager, geoMock, authManagerMock, metrics, permissionsManager, settingsManager, customZonesManager, zoneRecordsManager, networkMapController, nil, serviceManager, nil, nil, nil, nil, nil, nil, nil)
+	apiHandler, err := http2.NewAPIHandler(context.Background(), apiRouter, am, networksManager, resourcesManager, routersManager, groupsManager, geoMock, authManagerMock, metrics, permissionsManager, settingsManager, customZonesManager, zoneRecordsManager, networkMapController, nil, serviceManager, nil, nil, nil, nil, nil, nil, nil, nil)
 	if err != nil {
 		t.Fatalf("Failed to create API handler: %v", err)
 	}
@@ -267,7 +267,7 @@ func BuildApiBlackBoxWithDBStateAndPeerChannel(t testing_tools.TB, sqlFile strin
 	zoneRecordsManager := recordsManager.NewManager(store, am, permissionsManager)
 
 	apiRouter := mux.NewRouter().PathPrefix("/api").Subrouter()
-	apiHandler, err := http2.NewAPIHandler(context.Background(), apiRouter, am, networksManager, resourcesManager, routersManager, groupsManager, geoMock, authManagerMock, metrics, permissionsManager, settingsManager, customZonesManager, zoneRecordsManager, networkMapController, nil, serviceManager, nil, nil, nil, nil, nil, nil, nil)
+	apiHandler, err := http2.NewAPIHandler(context.Background(), apiRouter, am, networksManager, resourcesManager, routersManager, groupsManager, geoMock, authManagerMock, metrics, permissionsManager, settingsManager, customZonesManager, zoneRecordsManager, networkMapController, nil, serviceManager, nil, nil, nil, nil, nil, nil, nil, nil)
 	if err != nil {
 		t.Fatalf("Failed to create API handler: %v", err)
 	}