Mounted cloud credentials should not be world-readable (velero-io#8919)

Signed-off-by: Scott Seago <sseago@redhat.com>

Author: sseago

changelogs/unreleased/9094-sseago

@@ -0,0 +1 @@
+Mounted cloud credentials should not be world-readable

internal/credentials/file_store.go

@@ -71,7 +71,8 @@ func (n *namespacedFileStore) Path(selector *corev1api.SecretKeySelector) (strin
 
 	keyFilePath := filepath.Join(n.fsRoot, fmt.Sprintf("%s-%s", selector.Name, selector.Key))
 
-	file, err := n.fs.OpenFile(keyFilePath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
+	// owner RW perms, group R perms, no public perms
+	file, err := n.fs.OpenFile(keyFilePath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0640)
 	if err != nil {
 		return "", errors.Wrap(err, "unable to open credentials file for writing")
 	}

pkg/install/daemonset.go

@@ -23,6 +23,7 @@ import (
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/utils/ptr"
 
 	"github.com/vmware-tanzu/velero/internal/velero"
 )
@@ -177,6 +178,8 @@ func DaemonSet(namespace string, opts ...podTemplateOption) *appsv1.DaemonSet {
 				Name: "cloud-credentials",
 				VolumeSource: corev1.VolumeSource{
 					Secret: &corev1.SecretVolumeSource{
+						// read-only for Owner, Group, Public
+						DefaultMode: ptr.To(int32(0444)),
 						SecretName: "cloud-credentials",
 					},
 				},

pkg/install/deployment.go

@@ -24,6 +24,7 @@ import (
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/utils/ptr"
 
 	"github.com/vmware-tanzu/velero/internal/velero"
 	"github.com/vmware-tanzu/velero/pkg/builder"
@@ -404,6 +405,8 @@ func Deployment(namespace string, opts ...podTemplateOption) *appsv1.Deployment
 				Name: "cloud-credentials",
 				VolumeSource: corev1.VolumeSource{
 					Secret: &corev1.SecretVolumeSource{
+						// read-only for Owner, Group, Public
+						DefaultMode: ptr.To(int32(0444)),
 						SecretName: "cloud-credentials",
 					},
 				},