Restrict debug bundle log path and upload destinations

client/server/debug.go

@@ -7,18 +7,33 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"path/filepath"
 	"runtime/pprof"
+	"strings"
+	"time"
 
 	log "github.com/sirupsen/logrus"
+	"google.golang.org/grpc/codes"
+	gstatus "google.golang.org/grpc/status"
 
 	"github.com/netbirdio/netbird/client/internal/debug"
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
 	"github.com/netbirdio/netbird/client/proto"
 	mgmProto "github.com/netbirdio/netbird/shared/management/proto"
 	"github.com/netbirdio/netbird/version"
 )
 
 // DebugBundle creates a debug bundle and returns the location.
-func (s *Server) DebugBundle(_ context.Context, req *proto.DebugBundleRequest) (resp *proto.DebugBundleResponse, err error) {
+func (s *Server) DebugBundle(callerCtx context.Context, req *proto.DebugBundleRequest) (resp *proto.DebugBundleResponse, err error) {
+	if err := requirePrivilegeForUploadURL(callerCtx, req.GetUploadURL(), req.GetUploadInsecure()); err != nil {
+		return nil, err
+	}
+
+	// The UI log is opened as whoever asked for this bundle, so a caller only
+	// collects a log it owns (privileged callers excepted). ok is false on a
+	// socket that carries no identity, which skips the UI log.
+	callerID, callerIdentified := ipcauth.CallerIdentity(callerCtx)
+
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
 
@@ -68,6 +83,7 @@ func (s *Server) DebugBundle(_ context.Context, req *proto.DebugBundleRequest) (
 			SyncResponse:   syncResponse,
 			LogPath:        s.logFile,
 			UILogPath:      s.uiLogPath,
+			UILogOpener:    uiLogOpener(callerID, callerIdentified),
 			CPUProfile:     cpuProfileData,
 			CapturePath:    capturePath,
 			RefreshStatus:  refreshStatus,
@@ -90,7 +106,12 @@ func (s *Server) DebugBundle(_ context.Context, req *proto.DebugBundleRequest) (
 	if req.GetUploadURL() == "" {
 		return &proto.DebugBundleResponse{Path: path}, nil
 	}
-	key, err := debug.UploadDebugBundle(context.Background(), req.GetUploadURL(), s.config.ManagementURL.String(), path)
+	// Bound the upload: it runs while s.mutex is held, so an unresponsive
+	// destination must not block other RPCs indefinitely. Matches the mobile
+	// callers' timeout.
+	uploadCtx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
+	defer cancel()
+	key, err := debug.UploadDebugBundle(uploadCtx, req.GetUploadURL(), s.config.ManagementURL.String(), path, req.GetUploadInsecure())
 	if err != nil {
 		log.Errorf("failed to upload debug bundle to %s: %v", req.GetUploadURL(), err)
 		return &proto.DebugBundleResponse{Path: path, UploadFailureReason: err.Error()}, nil
@@ -138,12 +159,34 @@ func (s *Server) SetLogLevel(_ context.Context, req *proto.SetLogLevelRequest) (
 // RegisterUILog records the desktop UI's absolute log path so DebugBundle can
 // collect the GUI log. The daemon runs as root and can't resolve the user's
 // config dir, so the UI reports it. Last-writer-wins (one UI per socket).
-func (s *Server) RegisterUILog(_ context.Context, req *proto.RegisterUILogRequest) (*proto.RegisterUILogResponse, error) {
+//
+// The path arrives over an IPC any local user can reach and is later opened by
+// a root daemon, so it is constrained to the file name the UI writes and to a
+// local absolute path. Authorization happens when DebugBundle opens it: the
+// bundle refuses a file its requester does not own. A caller the daemon cannot
+// identify cannot register a path at all.
+func (s *Server) RegisterUILog(callerCtx context.Context, req *proto.RegisterUILogRequest) (*proto.RegisterUILogResponse, error) {
+	if _, ok := ipcauth.CallerIdentity(callerCtx); !ok {
+		return nil, gstatus.Error(codes.PermissionDenied,
+			"registering a UI log path requires a control channel that carries the caller's identity")
+	}
+
+	path := filepath.Clean(req.GetPath())
+	if !filepath.IsAbs(path) || filepath.Base(path) != uiLogFileName {
+		return nil, gstatus.Errorf(codes.InvalidArgument, "UI log path must be an absolute path ending in %s", uiLogFileName)
+	}
+	// filepath.IsAbs accepts a Windows UNC path (\\host\share\...) and a device
+	// path (\\.\, \\?\); opening one would make the root daemon reach a remote
+	// or device namespace. Require a plain local path.
+	if strings.HasPrefix(path, `\\`) {
+		return nil, gstatus.Error(codes.InvalidArgument, "UI log path must be a local path, not a UNC or device path")
+	}
+
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
 
-	s.uiLogPath = req.GetPath()
-	log.Infof("registered UI log path: %s", s.uiLogPath)
+	s.uiLogPath = path
+	log.Infof("registered UI log path %s", s.uiLogPath)
 
 	return &proto.RegisterUILogResponse{}, nil
 }

client/server/debug_gate.go

@@ -0,0 +1,98 @@
+//go:build !android && !ios
+
+package server
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"os"
+	"strings"
+
+	"google.golang.org/grpc/codes"
+	gstatus "google.golang.org/grpc/status"
+
+	"github.com/netbirdio/netbird/client/internal/debug"
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+	"github.com/netbirdio/netbird/upload-server/types"
+)
+
+// uiLogFileName is the only file name the daemon accepts as a UI log path,
+// shared with the bundle collector so the two cannot drift. It must also stay in
+// sync with the name the desktop UI writes (client/ui/uilogpath.go).
+const uiLogFileName = debug.UILogFile
+
+// uiLogOpener opens the registered UI log, and its rotated siblings, on behalf
+// of the caller requesting the bundle: OpenOwnedFile then collects the log only
+// when that caller owns it (or is privileged). identified is false on a socket
+// that carries no caller identity, in which case nothing is opened.
+func uiLogOpener(id ipcauth.Identity, identified bool) debug.LogOpener {
+	return func(path string) (*os.File, error) {
+		if !identified {
+			return nil, fmt.Errorf("bundle requester has no verified identity")
+		}
+		return ipcauth.OpenOwnedFile(id, path)
+	}
+}
+
+// requirePrivilegeForUploadURL restricts where the daemon may send a debug
+// bundle. The bundle holds the daemon's own logs and state, and the daemon
+// fetches the upload URL itself, so an unrestricted endpoint turns the daemon
+// into both an exfiltration channel and a request forwarder that reaches
+// services only it can talk to.
+//
+// The upload service NetBird publishes is open to any caller, since that is what
+// the CLI and the desktop UI use. Any other endpoint, self-hosted upload servers
+// included, requires a privileged caller. Plaintext is refused for everyone: the
+// daemon fetches the URL and then PUTs the bundle to whatever that fetch returns,
+// so an http hop is a place to intercept the bundle or the redirect.
+//
+// insecure relaxes transport security (http, or an untrusted TLS certificate)
+// for a self-hosted server. It weakens a root-privileged upload, so it is
+// refused for an unprivileged caller regardless of the host.
+func requirePrivilegeForUploadURL(ctx context.Context, rawURL string, insecure bool) error {
+	if rawURL == "" {
+		return nil
+	}
+
+	parsed, err := url.Parse(rawURL)
+	if err != nil {
+		return gstatus.Errorf(codes.InvalidArgument, "parse upload URL: %v", err)
+	}
+
+	// --insecure relaxes https to http or an untrusted certificate; it does not
+	// widen the URL to arbitrary schemes, so a host and http/https are required
+	// before the insecure branch takes over.
+	if parsed.Host == "" || (parsed.Scheme != "https" && parsed.Scheme != "http") {
+		return gstatus.Errorf(codes.InvalidArgument, "upload URL must be http or https with a host")
+	}
+
+	if insecure {
+		return denyPrivileged(ctx,
+			"uploading a debug bundle without transport security (--upload-bundle-insecure)",
+			ipcauth.ElevatedCommand("netbird debug bundle -U --upload-bundle-insecure --upload-bundle-url <url>"))
+	}
+
+	if parsed.Scheme != "https" {
+		return gstatus.Errorf(codes.InvalidArgument, "upload URL must use https, got scheme %q", parsed.Scheme)
+	}
+
+	if isDefaultUploadService(parsed) {
+		return nil
+	}
+
+	return denyPrivileged(ctx,
+		"uploading a debug bundle to an upload service other than the default one",
+		ipcauth.ElevatedCommand("netbird debug bundle -U --upload-bundle-url <url>"))
+}
+
+// isDefaultUploadService reports whether the URL points at the upload service
+// NetBird runs. Only the host is compared: the service's path may differ between
+// releases, and the host is what decides who receives the bundle.
+func isDefaultUploadService(parsed *url.URL) bool {
+	defaultURL, err := url.Parse(types.DefaultBundleURL)
+	if err != nil {
+		return false
+	}
+	return parsed.Scheme == defaultURL.Scheme && strings.EqualFold(parsed.Host, defaultURL.Host)
+}

client/server/debug_gate_test.go

@@ -0,0 +1,158 @@
+//go:build !android && !ios
+
+package server
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"google.golang.org/grpc/codes"
+	gstatus "google.golang.org/grpc/status"
+
+	"github.com/netbirdio/netbird/client/internal/ipcauth"
+	"github.com/netbirdio/netbird/client/proto"
+	"github.com/netbirdio/netbird/upload-server/types"
+)
+
+func TestRegisterUILogRefusesUnidentifiedCaller(t *testing.T) {
+	s := &Server{}
+
+	_, err := s.RegisterUILog(noIdentityCtx(), &proto.RegisterUILogRequest{
+		Path: filepath.Join(t.TempDir(), uiLogFileName),
+	})
+
+	if gstatus.Code(err) != codes.PermissionDenied {
+		t.Fatalf("code = %v, want PermissionDenied", gstatus.Code(err))
+	}
+}
+
+func TestRegisterUILogRefusesForeignPath(t *testing.T) {
+	secret := "/etc/shadow"
+	if runtime.GOOS == "windows" {
+		secret = `C:\Windows\System32\config\SAM`
+	}
+
+	tests := []struct {
+		name string
+		path string
+	}{
+		{"empty", ""},
+		{"relative", filepath.Join("netbird", uiLogFileName)},
+		{"another file", secret},
+		{"traversal onto another file", filepath.Join(t.TempDir(), "..", "..", secret)},
+		{"directory of the log", t.TempDir()},
+		{"unc path", `\\attacker\share\` + uiLogFileName},
+		{"device path", `\\.\C:\` + uiLogFileName},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			s := &Server{}
+
+			_, err := s.RegisterUILog(userCtx(), &proto.RegisterUILogRequest{Path: tc.path})
+
+			if gstatus.Code(err) != codes.InvalidArgument {
+				t.Fatalf("code = %v, want InvalidArgument", gstatus.Code(err))
+			}
+			if s.uiLogPath != "" {
+				t.Fatalf("path %q was recorded despite the refusal", s.uiLogPath)
+			}
+		})
+	}
+}
+
+func TestRegisterUILogRecordsPath(t *testing.T) {
+	s := &Server{}
+	path := filepath.Join(t.TempDir(), uiLogFileName)
+
+	if _, err := s.RegisterUILog(userCtx(), &proto.RegisterUILogRequest{Path: path}); err != nil {
+		t.Fatalf("register: %v", err)
+	}
+
+	if s.uiLogPath != path {
+		t.Fatalf("path = %q, want %q", s.uiLogPath, path)
+	}
+}
+
+// The UI log is opened as the bundle requester, so a second local user cannot
+// collect a log they do not own, and an unidentified requester collects nothing.
+func TestUILogOpenerBindsToRequester(t *testing.T) {
+	path := filepath.Join(t.TempDir(), uiLogFileName)
+	if err := os.WriteFile(path, []byte("log line"), 0600); err != nil {
+		t.Fatalf("write log: %v", err)
+	}
+
+	// A different unprivileged user than the file's owner: refused.
+	if _, err := uiLogOpener(unprivilegedIdentity(), true)(path); err == nil {
+		t.Fatal("expected a file the requester does not own to be refused")
+	}
+
+	// No verified identity: refused.
+	if _, err := uiLogOpener(ipcauth.Identity{}, false)(path); err == nil {
+		t.Fatal("expected an unidentified requester to be refused")
+	}
+
+	// The requester that owns the file: allowed. The test process created it, so
+	// its own identity is the owner (and a privileged runner is exempt anyway).
+	owner, err := ipcauth.CurrentProcessIdentity()
+	if err != nil {
+		t.Fatalf("current identity: %v", err)
+	}
+	f, err := uiLogOpener(owner, true)(path)
+	if err != nil {
+		t.Fatalf("expected the owning requester to be allowed, got %v", err)
+	}
+	_ = f.Close()
+}
+
+func TestRequirePrivilegeForUploadURL(t *testing.T) {
+	tests := []struct {
+		name     string
+		url      string
+		insecure bool
+		unprivOK bool
+		invalid  bool
+		rootAlso bool
+	}{
+		{name: "no upload", url: "", unprivOK: true},
+		{name: "default service", url: types.DefaultBundleURL, unprivOK: true},
+		{name: "default service, other path", url: "https://upload.debug.netbird.io/other", unprivOK: true},
+		{name: "loopback exfiltration endpoint", url: "https://127.0.0.1:8080/upload-url", rootAlso: true},
+		{name: "custom upload service", url: "https://attacker.example/upload-url", rootAlso: true},
+		{name: "plaintext default host", url: "http://upload.debug.netbird.io/upload-url", invalid: true},
+		{name: "plaintext custom host", url: "http://attacker.example/upload-url", invalid: true},
+		{name: "unsupported scheme", url: "file:///etc/shadow", invalid: true},
+		// insecure relaxes transport security; privileged only, whatever the host.
+		{name: "insecure http custom", url: "http://selfhosted.local/upload-url", insecure: true, rootAlso: true},
+		{name: "insecure https custom", url: "https://selfhosted.local/upload-url", insecure: true, rootAlso: true},
+		{name: "insecure default host", url: types.DefaultBundleURL, insecure: true, rootAlso: true},
+		// --insecure must not widen the URL to non-http(s) schemes or a hostless URL.
+		{name: "insecure file scheme", url: "file:///etc/shadow", insecure: true, invalid: true},
+		{name: "insecure hostless", url: "https:///upload-url", insecure: true, invalid: true},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			err := requirePrivilegeForUploadURL(userCtx(), tc.url, tc.insecure)
+
+			switch {
+			case tc.invalid:
+				if gstatus.Code(err) != codes.InvalidArgument {
+					t.Fatalf("code = %v, want InvalidArgument", gstatus.Code(err))
+				}
+				return
+			case tc.unprivOK:
+				assertAllowed(t, err)
+				return
+			default:
+				assertDenied(t, err)
+			}
+
+			if tc.rootAlso {
+				assertAllowed(t, requirePrivilegeForUploadURL(rootCtx(), tc.url, tc.insecure))
+			}
+		})
+	}
+}

client/server/server.go

@@ -72,6 +72,9 @@ type Server struct {
 	// RegisterUILog. Guarded by mutex. Consumed by DebugBundle so the bundle
 	// can collect the GUI log even though the daemon runs as root and can't
 	// resolve the user's config dir. Last-writer-wins (one UI per socket).
+	// DebugBundle opens it on behalf of the bundle requester and refuses a file
+	// that caller does not own, so a local user cannot read another user's log
+	// or a root-only file through it.
 	uiLogPath string
 
 	oauthAuthFlow oauthAuthFlow