File bypass-mountable-secrets-policy-imposed-by-SA-admission-plugin.patch of Package kubernetes1.23.33337
From: distributors-announce <distributors-announce@kubernetes.io>
Date: Tue, 2 Apr 2024 22:31:33 -0700
Subject: Fix CVE-2024-3177
---
.../pkg/admission/serviceaccount/admission.go | 21 +++
.../serviceaccount/admission_test.go | 127 ++++++++++++++++--
2 files changed, 134 insertions(+), 14 deletions(-)
Index: kubernetes-1.23.17/plugin/pkg/admission/serviceaccount/admission.go
===================================================================
--- kubernetes-1.23.17.orig/plugin/pkg/admission/serviceaccount/admission.go
+++ kubernetes-1.23.17/plugin/pkg/admission/serviceaccount/admission.go
@@ -338,6 +338,13 @@ func (s *Plugin) limitSecretReferences(s
}
}
}
+ for _, envFrom := range container.EnvFrom {
+ if envFrom.SecretRef != nil {
+ if !mountableSecrets.Has(envFrom.SecretRef.Name) {
+ return fmt.Errorf("init container %s with envFrom referencing secret.secretName=\"%s\" is not allowed because service account %s does not reference that secret", container.Name, envFrom.SecretRef.Name, serviceAccount.Name)
+ }
+ }
+ }
}
for _, container := range pod.Spec.Containers {
@@ -348,6 +355,13 @@ func (s *Plugin) limitSecretReferences(s
}
}
}
+ for _, envFrom := range container.EnvFrom {
+ if envFrom.SecretRef != nil {
+ if !mountableSecrets.Has(envFrom.SecretRef.Name) {
+ return fmt.Errorf("container %s with envFrom referencing secret.secretName=\"%s\" is not allowed because service account %s does not reference that secret", container.Name, envFrom.SecretRef.Name, serviceAccount.Name)
+ }
+ }
+ }
}
// limit pull secret references as well
@@ -389,6 +403,13 @@ func (s *Plugin) limitEphemeralContainer
}
}
}
+ for _, envFrom := range container.EnvFrom {
+ if envFrom.SecretRef != nil {
+ if !mountableSecrets.Has(envFrom.SecretRef.Name) {
+ return fmt.Errorf("ephemeral container %s with envFrom referencing secret.secretName=\"%s\" is not allowed because service account %s does not reference that secret", container.Name, envFrom.SecretRef.Name, serviceAccount.Name)
+ }
+ }
+ }
}
return nil
}
Index: kubernetes-1.23.17/plugin/pkg/admission/serviceaccount/admission_test.go
===================================================================
--- kubernetes-1.23.17.orig/plugin/pkg/admission/serviceaccount/admission_test.go
+++ kubernetes-1.23.17/plugin/pkg/admission/serviceaccount/admission_test.go
@@ -523,6 +523,25 @@ func TestAllowsReferencedSecret(t *testi
pod2 = &api.Pod{
Spec: api.PodSpec{
+ Containers: []api.Container{
+ {
+ Name: "container-1",
+ EnvFrom: []api.EnvFromSource{
+ {
+ SecretRef: &api.SecretEnvSource{
+ LocalObjectReference: api.LocalObjectReference{
+ Name: "foo"}}}},
+ },
+ },
+ },
+ }
+ attrs = admission.NewAttributesRecord(pod2, nil, api.Kind("Pod").WithVersion("version"), ns, "myname", api.Resource("pods").WithVersion("version"), "", admission.Create, &metav1.CreateOptions{}, false, nil)
+ if err := admissiontesting.WithReinvocationTesting(t, admit).Admit(context.TODO(), attrs, nil); err != nil {
+ t.Errorf("Unexpected error: %v", err)
+ }
+
+ pod2 = &api.Pod{
+ Spec: api.PodSpec{
InitContainers: []api.Container{
{
Name: "container-1",
@@ -547,6 +566,25 @@ func TestAllowsReferencedSecret(t *testi
pod2 = &api.Pod{
Spec: api.PodSpec{
+ InitContainers: []api.Container{
+ {
+ Name: "container-1",
+ EnvFrom: []api.EnvFromSource{
+ {
+ SecretRef: &api.SecretEnvSource{
+ LocalObjectReference: api.LocalObjectReference{
+ Name: "foo"}}}},
+ },
+ },
+ },
+ }
+ attrs = admission.NewAttributesRecord(pod2, nil, api.Kind("Pod").WithVersion("version"), ns, "myname", api.Resource("pods").WithVersion("version"), "", admission.Create, &metav1.CreateOptions{}, false, nil)
+ if err := admissiontesting.WithReinvocationTesting(t, admit).Admit(context.TODO(), attrs, nil); err != nil {
+ t.Errorf("Unexpected error: %v", err)
+ }
+
+ pod2 = &api.Pod{
+ Spec: api.PodSpec{
ServiceAccountName: DefaultServiceAccountName,
EphemeralContainers: []api.EphemeralContainer{
{
@@ -572,6 +610,28 @@ func TestAllowsReferencedSecret(t *testi
if err := admit.Validate(context.TODO(), attrs, nil); err != nil {
t.Errorf("Unexpected error: %v", err)
}
+
+ pod2 = &api.Pod{
+ Spec: api.PodSpec{
+ ServiceAccountName: DefaultServiceAccountName,
+ EphemeralContainers: []api.EphemeralContainer{
+ {
+ EphemeralContainerCommon: api.EphemeralContainerCommon{
+ Name: "container-2",
+ EnvFrom: []api.EnvFromSource{{
+ SecretRef: &api.SecretEnvSource{
+ LocalObjectReference: api.LocalObjectReference{
+ Name: "foo"}}}},
+ },
+ },
+ },
+ },
+ }
+ // validate enforces restrictions on secret mounts when operation==update and subresource==ephemeralcontainers"
+ attrs = admission.NewAttributesRecord(pod2, nil, api.Kind("Pod").WithVersion("version"), ns, "myname", api.Resource("pods").WithVersion("version"), "ephemeralcontainers", admission.Update, &metav1.UpdateOptions{}, false, nil)
+ if err := admit.Validate(context.TODO(), attrs, nil); err != nil {
+ t.Errorf("Unexpected error: %v", err)
+ }
}
func TestRejectsUnreferencedSecretVolumes(t *testing.T) {
@@ -628,25 +688,20 @@ func TestRejectsUnreferencedSecretVolume
pod2 = &api.Pod{
Spec: api.PodSpec{
- InitContainers: []api.Container{
+ Containers: []api.Container{
{
Name: "container-1",
- Env: []api.EnvVar{
+ EnvFrom: []api.EnvFromSource{
{
- Name: "env-1",
- ValueFrom: &api.EnvVarSource{
- SecretKeyRef: &api.SecretKeySelector{
- LocalObjectReference: api.LocalObjectReference{Name: "foo"},
- },
- },
- },
- },
+ SecretRef: &api.SecretEnvSource{
+ LocalObjectReference: api.LocalObjectReference{
+ Name: "foo"}}}},
},
},
},
}
attrs = admission.NewAttributesRecord(pod2, nil, api.Kind("Pod").WithVersion("version"), ns, "myname", api.Resource("pods").WithVersion("version"), "", admission.Create, &metav1.CreateOptions{}, false, nil)
- if err := admissiontesting.WithReinvocationTesting(t, admit).Admit(context.TODO(), attrs, nil); err == nil || !strings.Contains(err.Error(), "with envVar") {
+ if err := admissiontesting.WithReinvocationTesting(t, admit).Admit(context.TODO(), attrs, nil); err == nil || !strings.Contains(err.Error(), "with envFrom") {
t.Errorf("Unexpected error: %v", err)
}
@@ -682,6 +737,30 @@ func TestRejectsUnreferencedSecretVolume
pod2 = &api.Pod{
Spec: api.PodSpec{
ServiceAccountName: DefaultServiceAccountName,
+ InitContainers: []api.Container{
+ {
+ Name: "container-1",
+ EnvFrom: []api.EnvFromSource{
+ {
+ SecretRef: &api.SecretEnvSource{
+ LocalObjectReference: api.LocalObjectReference{
+ Name: "foo"}}}},
+ },
+ },
+ },
+ }
+ attrs = admission.NewAttributesRecord(pod2, nil, api.Kind("Pod").WithVersion("version"), ns, "myname", api.Resource("pods").WithVersion("version"), "", admission.Update, &metav1.UpdateOptions{}, false, nil)
+ if err := admissiontesting.WithReinvocationTesting(t, admit).Admit(context.TODO(), attrs, nil); err != nil {
+ t.Errorf("admit only enforces restrictions on secret mounts when operation==create. Unexpected error: %v", err)
+ }
+ attrs = admission.NewAttributesRecord(pod2, nil, api.Kind("Pod").WithVersion("version"), ns, "myname", api.Resource("pods").WithVersion("version"), "", admission.Create, &metav1.CreateOptions{}, false, nil)
+ if err := admit.Validate(context.TODO(), attrs, nil); err == nil || !strings.Contains(err.Error(), "with envFrom") {
+ t.Errorf("validate only enforces restrictions on secret mounts when operation==create and subresource==''. Unexpected error: %v", err)
+ }
+
+ pod2 = &api.Pod{
+ Spec: api.PodSpec{
+ ServiceAccountName: DefaultServiceAccountName,
EphemeralContainers: []api.EphemeralContainer{
{
EphemeralContainerCommon: api.EphemeralContainerCommon{
@@ -709,6 +788,27 @@ func TestRejectsUnreferencedSecretVolume
if err := admit.Validate(context.TODO(), attrs, nil); err == nil || !strings.Contains(err.Error(), "with envVar") {
t.Errorf("validate enforces restrictions on secret mounts when operation==update and subresource==ephemeralcontainers. Unexpected error: %v", err)
}
+
+ pod2 = &api.Pod{
+ Spec: api.PodSpec{
+ ServiceAccountName: DefaultServiceAccountName,
+ EphemeralContainers: []api.EphemeralContainer{
+ {
+ EphemeralContainerCommon: api.EphemeralContainerCommon{
+ Name: "container-2",
+ EnvFrom: []api.EnvFromSource{{
+ SecretRef: &api.SecretEnvSource{
+ LocalObjectReference: api.LocalObjectReference{
+ Name: "foo"}}}},
+ },
+ },
+ },
+ },
+ }
+ attrs = admission.NewAttributesRecord(pod2, nil, api.Kind("Pod").WithVersion("version"), ns, "myname", api.Resource("pods").WithVersion("version"), "ephemeralcontainers", admission.Update, &metav1.UpdateOptions{}, false, nil)
+ if err := admit.Validate(context.TODO(), attrs, nil); err == nil || !strings.Contains(err.Error(), "with envFrom") {
+ t.Errorf("validate enforces restrictions on secret mounts when operation==update and subresource==ephemeralcontainers. Unexpected error: %v", err)
+ }
}
func TestAllowUnreferencedSecretVolumesForPermissiveSAs(t *testing.T) {
