Restrict debug bundle log path and upload destinations

client/android/client.go

@@ -301,7 +301,7 @@ func (c *Client) DebugBundle(platformFiles PlatformFiles, anonymize bool) (strin
 	uploadCtx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
 	defer cancel()
 
-	key, err := debug.UploadDebugBundle(uploadCtx, types.DefaultBundleURL, cfg.ManagementURL.String(), path)
+	key, err := debug.UploadDebugBundle(uploadCtx, types.DefaultBundleURL, cfg.ManagementURL.String(), path, false)
 	if err != nil {
 		return "", fmt.Errorf("upload debug bundle: %w", err)
 	}

client/cmd/debug.go

@@ -29,8 +29,9 @@ const errCloseConnection = "Failed to close connection: %v"
 var (
 	logFileCount        uint32
 	systemInfoFlag      bool
-	uploadBundleFlag    bool
-	uploadBundleURLFlag string
+	uploadBundleFlag         bool
+	uploadBundleURLFlag      string
+	uploadBundleInsecureFlag bool
 )
 
 var debugCmd = &cobra.Command{
@@ -174,10 +175,11 @@ func debugBundle(cmd *cobra.Command, _ []string) error {
 	}
 	if uploadBundleFlag {
 		request.UploadURL = uploadBundleURLFlag
+		request.UploadInsecure = uploadBundleInsecureFlag
 	}
 	resp, err := client.DebugBundle(cmd.Context(), request)
 	if err != nil {
-		return fmt.Errorf("failed to bundle debug: %v", status.Convert(err).Message())
+		return daemonCallError("bundle debug", err)
 	}
 	cmd.Printf("Local file:\n%s\n", resp.GetPath())
 
@@ -373,10 +375,11 @@ func runForDuration(cmd *cobra.Command, args []string) error {
 	}
 	if uploadBundleFlag {
 		request.UploadURL = uploadBundleURLFlag
+		request.UploadInsecure = uploadBundleInsecureFlag
 	}
 	resp, err := client.DebugBundle(cmd.Context(), request)
 	if err != nil {
-		return fmt.Errorf("failed to bundle debug: %v", status.Convert(err).Message())
+		return daemonCallError("bundle debug", err)
 	}
 
 	if needsRestoreUp {
@@ -524,10 +527,12 @@ func init() {
 	debugBundleCmd.Flags().BoolVarP(&systemInfoFlag, "system-info", "S", true, "Adds system information to the debug bundle")
 	debugBundleCmd.Flags().BoolVarP(&uploadBundleFlag, "upload-bundle", "U", false, "Uploads the debug bundle to a server")
 	debugBundleCmd.Flags().StringVar(&uploadBundleURLFlag, "upload-bundle-url", types.DefaultBundleURL, "Service URL to get an URL to upload the debug bundle")
+	debugBundleCmd.Flags().BoolVar(&uploadBundleInsecureFlag, "upload-bundle-insecure", false, "Allow uploading to an http or untrusted-TLS upload server (self-hosted); requires root")
 
 	forCmd.Flags().Uint32VarP(&logFileCount, "log-file-count", "C", 1, "Number of rotated log files to include in debug bundle")
 	forCmd.Flags().BoolVarP(&systemInfoFlag, "system-info", "S", true, "Adds system information to the debug bundle")
 	forCmd.Flags().BoolVarP(&uploadBundleFlag, "upload-bundle", "U", false, "Uploads the debug bundle to a server")
 	forCmd.Flags().StringVar(&uploadBundleURLFlag, "upload-bundle-url", types.DefaultBundleURL, "Service URL to get an URL to upload the debug bundle")
+	forCmd.Flags().BoolVar(&uploadBundleInsecureFlag, "upload-bundle-insecure", false, "Allow uploading to an http or untrusted-TLS upload server (self-hosted); requires root")
 	forCmd.Flags().Bool("capture", false, "Capture packets during the debug duration and include in bundle")
 }

client/internal/debug/debug.go

@@ -229,7 +229,9 @@ scutil_dns.txt (macOS only):
 
 const (
 	clientLogFile = "client.log"
-	uiLogFile     = "gui-client.log"
+	// UILogFile is the desktop UI's log file name, exported so the daemon's
+	// RegisterUILog validation shares this single definition.
+	UILogFile     = "gui-client.log"
 	errorLogFile  = "netbird.err"
 	stdoutLogFile = "netbird.out"
 
@@ -248,6 +250,20 @@ type MetricsExporter interface {
 	Export(w io.Writer) error
 }
 
+// LogOpener opens a log file for inclusion in the bundle. It exists so that log
+// files whose path was supplied by an IPC caller can be opened under a check
+// the daemon defines, instead of being opened with the daemon's privileges
+// unconditionally.
+type LogOpener func(path string) (*os.File, error)
+
+func openLogFile(path string) (*os.File, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("open %s: %w", path, err)
+	}
+	return f, nil
+}
+
 type BundleGenerator struct {
 	anonymizer *anonymize.Anonymizer
 
@@ -257,6 +273,7 @@ type BundleGenerator struct {
 	syncResponse   *mgmProto.SyncResponse
 	logPath        string
 	uiLogPath      string
+	uiLogOpener    LogOpener
 	tempDir        string
 	statePath      string
 	cpuProfile     []byte
@@ -285,14 +302,20 @@ type GeneratorDependencies struct {
 	SyncResponse   *mgmProto.SyncResponse
 	LogPath        string
 	UILogPath      string // Absolute path to the desktop UI's gui-client.log, reported via RegisterUILog. Empty if no UI registered one.
-	TempDir        string // Directory for temporary bundle zip files. If empty, os.TempDir() is used.
-	StatePath      string // Path to the state file. If empty, the ServiceManager default path is used.
-	CPUProfile     []byte
-	CapturePath    string
-	RefreshStatus  func()
-	ClientMetrics  MetricsExporter
-	DaemonVersion  string
-	CliVersion     string
+	// UILogOpener opens the UI log and its rotated siblings. The path comes from
+	// a local IPC caller, so the daemon must not open it with plain os.Open: the
+	// opener is where the caller's right to that file is enforced. Defaults to
+	// os.Open, which is only correct where the path is not caller-supplied
+	// (mobile).
+	UILogOpener   LogOpener
+	TempDir       string // Directory for temporary bundle zip files. If empty, os.TempDir() is used.
+	StatePath     string // Path to the state file. If empty, the ServiceManager default path is used.
+	CPUProfile    []byte
+	CapturePath   string
+	RefreshStatus func()
+	ClientMetrics MetricsExporter
+	DaemonVersion string
+	CliVersion    string
 }
 
 func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGenerator {
@@ -302,6 +325,11 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 		logFileCount = 1
 	}
 
+	uiLogOpener := deps.UILogOpener
+	if uiLogOpener == nil {
+		uiLogOpener = openLogFile
+	}
+
 	return &BundleGenerator{
 		anonymizer: anonymize.NewAnonymizer(anonymize.DefaultAddresses()),
 
@@ -310,6 +338,7 @@ func NewBundleGenerator(deps GeneratorDependencies, cfg BundleConfig) *BundleGen
 		syncResponse:   deps.SyncResponse,
 		logPath:        deps.LogPath,
 		uiLogPath:      deps.UILogPath,
+		uiLogOpener:    uiLogOpener,
 		tempDir:        deps.TempDir,
 		statePath:      deps.StatePath,
 		cpuProfile:     deps.CPUProfile,
@@ -996,11 +1025,11 @@ func (g *BundleGenerator) addLogfile() error {
 
 	logDir := filepath.Dir(g.logPath)
 
-	if err := g.addSingleLogfile(g.logPath, clientLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, g.logPath, clientLogFile); err != nil {
 		return fmt.Errorf("add client log file to zip: %w", err)
 	}
 
-	g.addRotatedLogFiles(logDir, clientLogPrefix)
+	g.addRotatedLogFiles(openLogFile, logDir, clientLogPrefix)
 
 	stdErrLogPath := filepath.Join(logDir, errorLogFile)
 	stdoutLogPath := filepath.Join(logDir, stdoutLogFile)
@@ -1009,11 +1038,11 @@ func (g *BundleGenerator) addLogfile() error {
 		stdoutLogPath = darwinStdoutLogPath
 	}
 
-	if err := g.addSingleLogfile(stdErrLogPath, errorLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, stdErrLogPath, errorLogFile); err != nil {
 		log.Warnf("Failed to add %s to zip: %v", errorLogFile, err)
 	}
 
-	if err := g.addSingleLogfile(stdoutLogPath, stdoutLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, stdoutLogPath, stdoutLogFile); err != nil {
 		log.Warnf("Failed to add %s to zip: %v", stdoutLogFile, err)
 	}
 
@@ -1030,18 +1059,18 @@ func (g *BundleGenerator) addUILog() error {
 		return nil
 	}
 
-	if err := g.addSingleLogfile(g.uiLogPath, uiLogFile); err != nil {
+	if err := g.addSingleLogfile(g.uiLogOpener, g.uiLogPath, UILogFile); err != nil {
 		return fmt.Errorf("add UI log file to zip: %w", err)
 	}
 
-	g.addRotatedLogFiles(filepath.Dir(g.uiLogPath), uiLogPrefix)
+	g.addRotatedLogFiles(g.uiLogOpener, filepath.Dir(g.uiLogPath), uiLogPrefix)
 
 	return nil
 }
 
 // addSingleLogfile adds a single log file to the archive
-func (g *BundleGenerator) addSingleLogfile(logPath, targetName string) error {
-	logFile, err := os.Open(logPath)
+func (g *BundleGenerator) addSingleLogfile(open LogOpener, logPath, targetName string) error {
+	logFile, err := open(logPath)
 	if err != nil {
 		return fmt.Errorf("open log file %s: %w", targetName, err)
 	}
@@ -1066,8 +1095,8 @@ func (g *BundleGenerator) addSingleLogfile(logPath, targetName string) error {
 }
 
 // addSingleLogFileGz adds a single gzipped log file to the archive
-func (g *BundleGenerator) addSingleLogFileGz(logPath, targetName string) error {
-	f, err := os.Open(logPath)
+func (g *BundleGenerator) addSingleLogFileGz(open LogOpener, logPath, targetName string) error {
+	f, err := open(logPath)
 	if err != nil {
 		return fmt.Errorf("open gz log file %s: %w", targetName, err)
 	}
@@ -1114,7 +1143,7 @@ func (g *BundleGenerator) addSingleLogFileGz(logPath, targetName string) error {
 // addRotatedLogFiles adds rotated log files to the bundle based on logFileCount.
 // prefix is the base log name without extension (e.g. "client", "gui-client");
 // the glob matches both files rotated by us and by logrotate on linux.
-func (g *BundleGenerator) addRotatedLogFiles(logDir, prefix string) {
+func (g *BundleGenerator) addRotatedLogFiles(open LogOpener, logDir, prefix string) {
 	if g.logFileCount == 0 {
 		return
 	}
@@ -1154,9 +1183,9 @@ func (g *BundleGenerator) addRotatedLogFiles(logDir, prefix string) {
 	for i := 0; i < maxFiles; i++ {
 		name := filepath.Base(files[i])
 		if strings.HasSuffix(name, ".gz") {
-			err = g.addSingleLogFileGz(files[i], name)
+			err = g.addSingleLogFileGz(open, files[i], name)
 		} else {
-			err = g.addSingleLogfile(files[i], name)
+			err = g.addSingleLogfile(open, files[i], name)
 		}
 		if err != nil {
 			log.Warnf("failed to add rotated log %s: %v", name, err)

client/internal/debug/debug_ios.go

@@ -27,7 +27,7 @@ func (g *BundleGenerator) addPlatformLog() error {
 	}
 
 	swiftLogPath := filepath.Join(filepath.Dir(g.logPath), swiftLogFile)
-	if err := g.addSingleLogfile(swiftLogPath, swiftLogFile); err != nil {
+	if err := g.addSingleLogfile(openLogFile, swiftLogPath, swiftLogFile); err != nil {
 		// The Swift log is best-effort: the app may not have written it yet.
 		log.Warnf("failed to add %s to debug bundle: %v", swiftLogFile, err)
 	}

client/internal/debug/debug_logfiles_test.go

@@ -97,7 +97,7 @@ func runAddRotatedLogFilesPrefix(t *testing.T, dir, prefix string, logFileCount
 		archive:      zip.NewWriter(&buf),
 		logFileCount: logFileCount,
 	}
-	g.addRotatedLogFiles(dir, prefix)
+	g.addRotatedLogFiles(openLogFile, dir, prefix)
 	require.NoError(t, g.archive.Close())
 
 	zr, err := zip.NewReader(bytes.NewReader(buf.Bytes()), int64(buf.Len()))

client/internal/debug/uilog_test.go

@@ -0,0 +1,62 @@
+package debug
+
+import (
+	"archive/zip"
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// bundleEntries generates a bundle with the given generator and returns the
+// set of entry names in the resulting archive.
+func bundleEntries(t *testing.T, g *BundleGenerator) map[string]struct{} {
+	t.Helper()
+
+	path, err := g.Generate()
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = os.Remove(path) })
+
+	data, err := os.ReadFile(path)
+	require.NoError(t, err)
+
+	zr, err := zip.NewReader(bytes.NewReader(data), int64(len(data)))
+	require.NoError(t, err)
+
+	names := make(map[string]struct{}, len(zr.File))
+	for _, f := range zr.File {
+		names[f.Name] = struct{}{}
+	}
+	return names
+}
+
+func TestBundleIncludesUILogWhenOpenerAllows(t *testing.T) {
+	path := filepath.Join(t.TempDir(), UILogFile)
+	require.NoError(t, os.WriteFile(path, []byte("gui log"), 0600))
+
+	g := NewBundleGenerator(GeneratorDependencies{
+		UILogPath:   path,
+		UILogOpener: openLogFile,
+	}, BundleConfig{})
+
+	require.Contains(t, bundleEntries(t, g), UILogFile)
+}
+
+// A UILogOpener that refuses (as the ownership check does for a foreign file)
+// keeps the UI log out of the bundle without failing bundle generation.
+func TestBundleExcludesUILogWhenOpenerRefuses(t *testing.T) {
+	path := filepath.Join(t.TempDir(), UILogFile)
+	require.NoError(t, os.WriteFile(path, []byte("secret"), 0600))
+
+	g := NewBundleGenerator(GeneratorDependencies{
+		UILogPath: path,
+		UILogOpener: func(string) (*os.File, error) {
+			return nil, fmt.Errorf("not owned by the caller")
+		},
+	}, BundleConfig{})
+
+	require.NotContains(t, bundleEntries(t, g), UILogFile)
+}

client/internal/debug/upload.go

@@ -3,10 +3,12 @@ package debug
 import (
 	"context"
 	"crypto/sha256"
+	"crypto/tls"
 	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
+	neturl "net/url"
 	"os"
 
 	"github.com/netbirdio/netbird/upload-server/types"
@@ -14,20 +16,80 @@ import (
 
 const maxBundleUploadSize = 50 * 1024 * 1024
 
-func UploadDebugBundle(ctx context.Context, url, managementURL, filePath string) (key string, err error) {
-	response, err := getUploadURL(ctx, url, managementURL)
+// requireHTTPS refuses any URL the daemon would fetch or upload to that is not
+// https. The daemon runs as root and the bundle carries its logs and state, so a
+// plaintext hop is a place to intercept the bundle or the presigned redirect.
+// The server-side gate already enforces this for the desktop path; this also
+// covers the mobile and job-runner callers that reach this package directly.
+// Skipped when the caller opted into an insecure upload (self-hosted server).
+func requireHTTPS(what, rawURL string) error {
+	parsed, err := neturl.Parse(rawURL)
+	if err != nil {
+		return fmt.Errorf("parse %s: %w", what, err)
+	}
+	if parsed.Scheme != "https" {
+		return fmt.Errorf("%s must use https, got scheme %q", what, parsed.Scheme)
+	}
+	return nil
+}
+
+// uploadClient returns the HTTP client for the upload requests. The default
+// client verifies TLS and refuses a redirect that would downgrade to a non-https
+// hop, so a bundle can never leave over http after an https start. The insecure
+// variant accepts http and untrusted certificates, and is only reachable for a
+// privileged caller that passed --upload-bundle-insecure (see
+// requirePrivilegeForUploadURL).
+func uploadClient(insecure bool) *http.Client {
+	if !insecure {
+		return &http.Client{CheckRedirect: rejectInsecureRedirect}
+	}
+	return &http.Client{
+		Transport: &http.Transport{
+			//nolint:gosec // opt-in, privileged, self-hosted upload servers
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: true, MinVersion: tls.VersionTLS12},
+		},
+	}
+}
+
+// rejectInsecureRedirect refuses a redirect to a non-https target and keeps the
+// standard library's 10-hop limit that a custom CheckRedirect would otherwise
+// disable.
+func rejectInsecureRedirect(req *http.Request, via []*http.Request) error {
+	if req.URL.Scheme != "https" {
+		return fmt.Errorf("refusing redirect to non-https URL %s", req.URL.Redacted())
+	}
+	if len(via) >= 10 {
+		return fmt.Errorf("stopped after 10 redirects")
+	}
+	return nil
+}
+
+func UploadDebugBundle(ctx context.Context, url, managementURL, filePath string, insecure bool) (key string, err error) {
+	if !insecure {
+		if err := requireHTTPS("upload service URL", url); err != nil {
+			return "", err
+		}
+	}
+
+	response, err := getUploadURL(ctx, url, managementURL, insecure)
 	if err != nil {
 		return "", err
 	}
 
-	err = upload(ctx, filePath, response)
+	if !insecure {
+		if err := requireHTTPS("upload URL from service", response.URL); err != nil {
+			return "", err
+		}
+	}
+
+	err = upload(ctx, filePath, response, insecure)
 	if err != nil {
 		return "", err
 	}
 	return response.Key, nil
 }
 
-func upload(ctx context.Context, filePath string, response *types.GetURLResponse) error {
+func upload(ctx context.Context, filePath string, response *types.GetURLResponse, insecure bool) error {
 	fileData, err := os.Open(filePath)
 	if err != nil {
 		return fmt.Errorf("open file: %w", err)
@@ -52,7 +114,7 @@ func upload(ctx context.Context, filePath string, response *types.GetURLResponse
 	req.ContentLength = stat.Size()
 	req.Header.Set("Content-Type", "application/octet-stream")
 
-	putResp, err := http.DefaultClient.Do(req)
+	putResp, err := uploadClient(insecure).Do(req)
 	if err != nil {
 		return fmt.Errorf("upload failed: %v", err)
 	}
@@ -65,7 +127,7 @@ func upload(ctx context.Context, filePath string, response *types.GetURLResponse
 	return nil
 }
 
-func getUploadURL(ctx context.Context, url string, managementURL string) (*types.GetURLResponse, error) {
+func getUploadURL(ctx context.Context, url string, managementURL string, insecure bool) (*types.GetURLResponse, error) {
 	id := getURLHash(managementURL)
 	getReq, err := http.NewRequestWithContext(ctx, "GET", url+"?id="+id, nil)
 	if err != nil {
@@ -74,7 +136,7 @@ func getUploadURL(ctx context.Context, url string, managementURL string) (*types
 
 	getReq.Header.Set(types.ClientHeader, types.ClientHeaderValue)
 
-	resp, err := http.DefaultClient.Do(getReq)
+	resp, err := uploadClient(insecure).Do(getReq)
 	if err != nil {
 		return nil, fmt.Errorf("get presigned URL: %w", err)
 	}

client/internal/debug/upload_test.go

@@ -43,7 +43,7 @@ func TestUpload(t *testing.T) {
 	fileContent := []byte("test file content")
 	err := os.WriteFile(file, fileContent, 0640)
 	require.NoError(t, err)
-	key, err := UploadDebugBundle(context.Background(), testURL+types.GetURLPath, testURL, file)
+	key, err := UploadDebugBundle(context.Background(), testURL+types.GetURLPath, testURL, file, true)
 	require.NoError(t, err)
 	id := getURLHash(testURL)
 	require.Contains(t, key, id+"/")

client/internal/ipcauth/ownedfile.go

@@ -0,0 +1,63 @@
+package ipcauth
+
+import (
+	"fmt"
+	"os"
+)
+
+// OpenOwnedFile opens path for reading on behalf of the IPC caller identified by
+// id, and fails unless the opened file is a regular file that id owns.
+//
+// It exists for the paths a local caller hands to the daemon over the IPC. The
+// daemon runs as root, so opening such a path unchecked lets any local user read
+// any file through it. Ownership is the invariant that keeps the daemon from
+// reading, with its own privileges, a file the caller could not read itself: a
+// symlink or hard link planted at the path resolves to a file someone else owns
+// and is refused.
+//
+// The check is made against the open descriptor rather than the path, so
+// swapping the path between the check and the read cannot change the answer.
+//
+// A privileged caller is exempt: it can read the file directly, so refusing it
+// here would protect nothing. The regular-file requirement still applies to
+// everyone, since a fifo or device planted at the path is never a log file.
+func OpenOwnedFile(id Identity, path string) (*os.File, error) {
+	f, err := openForRead(path)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := checkOwnership(id, f); err != nil {
+		if cerr := f.Close(); cerr != nil {
+			return nil, fmt.Errorf("%w (close: %v)", err, cerr)
+		}
+		return nil, err
+	}
+
+	return f, nil
+}
+
+func checkOwnership(id Identity, f *os.File) error {
+	info, err := f.Stat()
+	if err != nil {
+		return fmt.Errorf("stat %s: %w", f.Name(), err)
+	}
+
+	if !info.Mode().IsRegular() {
+		return fmt.Errorf("%s is not a regular file", f.Name())
+	}
+
+	if IsPrivilegedCaller(id) {
+		return nil
+	}
+
+	owned, err := fileOwnedBy(id, f)
+	if err != nil {
+		return fmt.Errorf("read owner of %s: %w", f.Name(), err)
+	}
+	if !owned {
+		return fmt.Errorf("%s is not owned by the caller (%s)", f.Name(), id)
+	}
+
+	return nil
+}

client/internal/ipcauth/ownedfile_test.go

@@ -0,0 +1,64 @@
+package ipcauth
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// otherIdentity is an unprivileged caller that owns nothing the test creates.
+func otherIdentity(t *testing.T) Identity {
+	t.Helper()
+	if runtime.GOOS == "windows" {
+		return Identity{SID: "S-1-5-21-1-2-3-1001"}
+	}
+	return Identity{UID: uint32(os.Geteuid() + 1), GID: uint32(os.Getegid() + 1)}
+}
+
+func TestOpenOwnedFileReadsFileOwnedByCaller(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, os.WriteFile(path, []byte("hello"), 0600))
+
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	f, err := OpenOwnedFile(id, path)
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = f.Close() })
+
+	content, err := io.ReadAll(f)
+	require.NoError(t, err)
+	require.Equal(t, "hello", string(content))
+}
+
+func TestOpenOwnedFileRefusesFileOwnedByAnother(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, os.WriteFile(path, []byte("secret"), 0600))
+
+	_, err := OpenOwnedFile(otherIdentity(t), path)
+	require.ErrorContains(t, err, "not owned by the caller")
+}
+
+func TestOpenOwnedFileRefusesNonRegularFile(t *testing.T) {
+	dir := t.TempDir()
+
+	// The caller owns the directory, so this is the regular-file requirement
+	// talking, not the ownership check.
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	_, err = OpenOwnedFile(id, dir)
+	require.ErrorContains(t, err, "not a regular file")
+}
+
+func TestOpenOwnedFileRefusesMissingFile(t *testing.T) {
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	_, err = OpenOwnedFile(id, filepath.Join(t.TempDir(), "absent.log"))
+	require.Error(t, err)
+}

client/internal/ipcauth/ownedfile_unix.go

@@ -0,0 +1,35 @@
+//go:build !windows
+
+package ipcauth
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+)
+
+// openForRead opens a caller-supplied path without following a symlink at its
+// final component and without blocking: a fifo planted at the path would
+// otherwise stall the open until a writer appears, and the daemon holds a lock
+// while it collects the file.
+func openForRead(path string) (*os.File, error) {
+	f, err := os.OpenFile(path, os.O_RDONLY|syscall.O_NOFOLLOW|syscall.O_NONBLOCK, 0)
+	if err != nil {
+		return nil, fmt.Errorf("open %s: %w", path, err)
+	}
+	return f, nil
+}
+
+func fileOwnedBy(id Identity, f *os.File) (bool, error) {
+	info, err := f.Stat()
+	if err != nil {
+		return false, err
+	}
+
+	stat, ok := info.Sys().(*syscall.Stat_t)
+	if !ok {
+		return false, fmt.Errorf("no owner information in %T", info.Sys())
+	}
+
+	return stat.Uid == id.UID, nil
+}

client/internal/ipcauth/ownedfile_unix_test.go

@@ -0,0 +1,57 @@
+//go:build !windows
+
+package ipcauth
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+// A symlink is the shape the arbitrary-read attempt takes: the caller owns the
+// link, the file it points at belongs to someone else.
+func TestOpenOwnedFileRefusesSymlink(t *testing.T) {
+	dir := t.TempDir()
+	target := filepath.Join(dir, "target.log")
+	require.NoError(t, os.WriteFile(target, []byte("secret"), 0600))
+
+	link := filepath.Join(dir, "gui-client.log")
+	require.NoError(t, os.Symlink(target, link))
+
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	_, err = OpenOwnedFile(id, link)
+	// O_NOFOLLOW on a symlink reports ELOOP on Linux/Darwin and EMLINK on FreeBSD.
+	if !errors.Is(err, syscall.ELOOP) && !errors.Is(err, syscall.EMLINK) {
+		t.Fatalf("symlink open: got %v, want ELOOP or EMLINK", err)
+	}
+}
+
+// A fifo would block the open until a writer showed up, stalling the daemon
+// while it holds its lock.
+func TestOpenOwnedFileRefusesFifoWithoutBlocking(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, syscall.Mkfifo(path, 0600))
+
+	id, err := CurrentProcessIdentity()
+	require.NoError(t, err)
+
+	done := make(chan error, 1)
+	go func() {
+		_, err := OpenOwnedFile(id, path)
+		done <- err
+	}()
+
+	select {
+	case err := <-done:
+		require.ErrorContains(t, err, "not a regular file")
+	case <-time.After(5 * time.Second):
+		t.Fatal("opening a fifo blocked")
+	}
+}

client/internal/ipcauth/ownedfile_windows.go

@@ -0,0 +1,37 @@
+//go:build windows
+
+package ipcauth
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/sys/windows"
+)
+
+func openForRead(path string) (*os.File, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("open %s: %w", path, err)
+	}
+	return f, nil
+}
+
+// fileOwnedBy compares the file's owner SID with the caller's. Files an elevated
+// process creates are owned by BUILTIN\Administrators rather than by the user,
+// but such a caller is privileged and never reaches this check.
+func fileOwnedBy(id Identity, f *os.File) (bool, error) {
+	// x/sys/windows GetSecurityInfo frees the OS buffer itself and returns a
+	// Go-heap copy, so there is nothing to LocalFree here.
+	sd, err := windows.GetSecurityInfo(windows.Handle(f.Fd()), windows.SE_FILE_OBJECT, windows.OWNER_SECURITY_INFORMATION)
+	if err != nil {
+		return false, fmt.Errorf("read security info: %w", err)
+	}
+
+	owner, _, err := sd.Owner()
+	if err != nil {
+		return false, fmt.Errorf("read owner: %w", err)
+	}
+
+	return id.SID != "" && owner.String() == id.SID, nil
+}

client/internal/ipcauth/ownedfile_windows_test.go

@@ -0,0 +1,57 @@
+//go:build windows
+
+package ipcauth
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"golang.org/x/sys/windows"
+)
+
+// fileOwnerSID reads the owner SID of path the same way OpenOwnedFile does, so
+// the test can construct an Identity that matches (or deliberately does not).
+func fileOwnerSID(t *testing.T, path string) string {
+	t.Helper()
+	f, err := os.Open(path)
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = f.Close() })
+
+	sd, err := windows.GetSecurityInfo(windows.Handle(f.Fd()), windows.SE_FILE_OBJECT, windows.OWNER_SECURITY_INFORMATION)
+	require.NoError(t, err)
+	owner, _, err := sd.Owner()
+	require.NoError(t, err)
+	return owner.String()
+}
+
+// The allow branch of fileOwnedBy is the SID-equality path the legitimate GUI
+// flow depends on. Running elevated, a created file is owned by
+// BUILTIN\Administrators; an Identity carrying that SID with Elevated=false and
+// no groups is unprivileged by IsPrivileged (which reads the token, not the
+// SID's RID), so this exercises the real GetSecurityInfo equality rather than
+// the privileged-caller shortcut.
+func TestOpenOwnedFileWindowsOwnerMatchAllows(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, os.WriteFile(path, []byte("hello"), 0600))
+
+	ownerSID := fileOwnerSID(t, path)
+	id := Identity{SID: ownerSID}
+	require.False(t, id.IsPrivileged(), "identity built from the owner SID must be unprivileged for this to test the match path")
+
+	f, err := OpenOwnedFile(id, path)
+	require.NoError(t, err)
+	_ = f.Close()
+}
+
+func TestOpenOwnedFileWindowsOwnerMismatchRefuses(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "gui-client.log")
+	require.NoError(t, os.WriteFile(path, []byte("secret"), 0600))
+
+	other := Identity{SID: "S-1-5-21-9-9-9-9999"}
+	require.False(t, other.IsPrivileged())
+
+	_, err := OpenOwnedFile(other, path)
+	require.ErrorContains(t, err, "not owned by the caller")
+}

client/ios/NetBirdSDK/client.go

@@ -262,7 +262,7 @@ func (c *Client) DebugBundle(anonymize bool) (string, error) {
 	uploadCtx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
 	defer cancel()
 
-	key, err := debug.UploadDebugBundle(uploadCtx, types.DefaultBundleURL, cfg.ManagementURL.String(), path)
+	key, err := debug.UploadDebugBundle(uploadCtx, types.DefaultBundleURL, cfg.ManagementURL.String(), path, false)
 	if err != nil {
 		return "", fmt.Errorf("upload debug bundle: %w", err)
 	}

client/jobexec/executor.go

@@ -54,7 +54,7 @@ func (e *Executor) BundleJob(ctx context.Context, debugBundleDependencies debug.
 		}
 	}()
 
-	key, err := debug.UploadDebugBundle(ctx, types.DefaultBundleURL, mgmURL, path)
+	key, err := debug.UploadDebugBundle(ctx, types.DefaultBundleURL, mgmURL, path, false)
 	if err != nil {
 		log.Errorf("failed to upload debug bundle: %v", err)
 		return "", fmt.Errorf("upload debug bundle: %w", err)

client/proto/daemon.pb.go

@@ -2771,14 +2771,18 @@ func (x *ForwardingRulesResponse) GetRules() []*ForwardingRule {
 
 // DebugBundler
 type DebugBundleRequest struct {
-	state         protoimpl.MessageState `protogen:"open.v1"`
-	Anonymize     bool                   `protobuf:"varint,1,opt,name=anonymize,proto3" json:"anonymize,omitempty"`
-	SystemInfo    bool                   `protobuf:"varint,3,opt,name=systemInfo,proto3" json:"systemInfo,omitempty"`
-	UploadURL     string                 `protobuf:"bytes,4,opt,name=uploadURL,proto3" json:"uploadURL,omitempty"`
-	LogFileCount  uint32                 `protobuf:"varint,5,opt,name=logFileCount,proto3" json:"logFileCount,omitempty"`
-	CliVersion    string                 `protobuf:"bytes,6,opt,name=cliVersion,proto3" json:"cliVersion,omitempty"`
-	unknownFields protoimpl.UnknownFields
-	sizeCache     protoimpl.SizeCache
+	state        protoimpl.MessageState `protogen:"open.v1"`
+	Anonymize    bool                   `protobuf:"varint,1,opt,name=anonymize,proto3" json:"anonymize,omitempty"`
+	SystemInfo   bool                   `protobuf:"varint,3,opt,name=systemInfo,proto3" json:"systemInfo,omitempty"`
+	UploadURL    string                 `protobuf:"bytes,4,opt,name=uploadURL,proto3" json:"uploadURL,omitempty"`
+	LogFileCount uint32                 `protobuf:"varint,5,opt,name=logFileCount,proto3" json:"logFileCount,omitempty"`
+	CliVersion   string                 `protobuf:"bytes,6,opt,name=cliVersion,proto3" json:"cliVersion,omitempty"`
+	// uploadInsecure allows uploading to an http endpoint or one with an
+	// untrusted TLS certificate. Restricted to privileged callers; for
+	// self-hosted upload servers.
+	UploadInsecure bool `protobuf:"varint,7,opt,name=uploadInsecure,proto3" json:"uploadInsecure,omitempty"`
+	unknownFields  protoimpl.UnknownFields
+	sizeCache      protoimpl.SizeCache
 }
 
 func (x *DebugBundleRequest) Reset() {
@@ -2846,6 +2850,13 @@ func (x *DebugBundleRequest) GetCliVersion() string {
 	return ""
 }
 
+func (x *DebugBundleRequest) GetUploadInsecure() bool {
+	if x != nil {
+		return x.UploadInsecure
+	}
+	return false
+}
+
 type DebugBundleResponse struct {
 	state               protoimpl.MessageState `protogen:"open.v1"`
 	Path                string                 `protobuf:"bytes,1,opt,name=path,proto3" json:"path,omitempty"`
@@ -7242,7 +7253,7 @@ const file_daemon_proto_rawDesc = "" +
 	"\x12translatedHostname\x18\x04 \x01(\tR\x12translatedHostname\x128\n" +
 	"\x0etranslatedPort\x18\x05 \x01(\v2\x10.daemon.PortInfoR\x0etranslatedPort\"G\n" +
 	"\x17ForwardingRulesResponse\x12,\n" +
-	"\x05rules\x18\x01 \x03(\v2\x16.daemon.ForwardingRuleR\x05rules\"\xb4\x01\n" +
+	"\x05rules\x18\x01 \x03(\v2\x16.daemon.ForwardingRuleR\x05rules\"\xdc\x01\n" +
 	"\x12DebugBundleRequest\x12\x1c\n" +
 	"\tanonymize\x18\x01 \x01(\bR\tanonymize\x12\x1e\n" +
 	"\n" +
@@ -7252,7 +7263,8 @@ const file_daemon_proto_rawDesc = "" +
 	"\flogFileCount\x18\x05 \x01(\rR\flogFileCount\x12\x1e\n" +
 	"\n" +
 	"cliVersion\x18\x06 \x01(\tR\n" +
-	"cliVersion\"}\n" +
+	"cliVersion\x12&\n" +
+	"\x0euploadInsecure\x18\a \x01(\bR\x0euploadInsecure\"}\n" +
 	"\x13DebugBundleResponse\x12\x12\n" +
 	"\x04path\x18\x01 \x01(\tR\x04path\x12 \n" +
 	"\vuploadedKey\x18\x02 \x01(\tR\vuploadedKey\x120\n" +

client/proto/daemon.proto

@@ -536,6 +536,10 @@ message DebugBundleRequest {
   string uploadURL = 4;
   uint32 logFileCount = 5;
   string cliVersion = 6;
+  // uploadInsecure allows uploading to an http endpoint or one with an
+  // untrusted TLS certificate. Restricted to privileged callers; for
+  // self-hosted upload servers.
+  bool uploadInsecure = 7;
 }
 
 message DebugBundleResponse {

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