lacework-global-234
1.4 Ensure That There Are Only GCP-Managed Service Account Keys for Each Service Account (Automated)
Profile Applicability
• Level 1
Description
User managed service accounts should not have user-managed keys.
Rationale
Anyone who has access to the keys will be able to access resources through the service account. GCP-managed keys are used by Cloud Platform services such as App Engine and Compute Engine. These keys cannot be downloaded. Google will keep the keys and automatically rotate them on an approximately weekly basis. User-managed keys are created, downloadable, and managed by users. They expire 10 years from creation.
For user-managed keys, the user has to take ownership of key management activities which include:
- Key storage
- Key distribution
- Key revocation
- Key rotation
- Protecting the keys from unauthorized users
- Key recovery
Even with key owner precautions, keys can be easily leaked by common development malpractices like checking keys into the source code or leaving them in the Downloads directory, or accidentally leaving them on support blogs/channels.
It is recommended to prevent user-managed service account keys.
Impact
Deleting user-managed Service Account Keys may break communication with the applications using the corresponding keys.
Audit
From Console:
Go to the IAM page in the GCP Console using
https://console.cloud.google.com/iam-admin/iam
In the left navigation pane, click
Service accounts
. All service accounts and their corresponding keys are listed.Click the service accounts and check if keys exist.
From Command Line:
List All the service accounts:
gcloud iam service-accounts list
Identify user-managed service accounts as such account EMAIL
ends with iam.gserviceaccount.com
For each user-managed service account, list the keys managed by the user:
gcloud iam service-accounts keys list --iam-account=<Service Account> --managed-by=user
No keys should be listed.
Remediation
From Console:
Go to the IAM page in the GCP Console using
https://console.cloud.google.com/iam-admin/iam
In the left navigation pane, click
Service accounts
. All service accounts and their corresponding keys are listed.Click the service account.
Click the
edit
and delete the keys.
From Command Line:
To delete a user managed Service Account Key,
gcloud iam service-accounts keys delete --iam-account=<user-managed-service-account-EMAIL> <KEY-ID>
Prevention:
You can disable service account key creation through the Disable service account key creation
Organization policy by visiting https://console.cloud.google.com/iam-admin/orgpolicies/iam-disableServiceAccountKeyCreation. Learn more at: https://cloud.google.com/resource-manager/docs/organization-policy/restricting-service-accounts
In addition, if you do not need to have service accounts in your project, you can also prevent the creation of service accounts through the Disable service account creation
Organization policy: https://console.cloud.google.com/iam-admin/orgpolicies/iam-disableServiceAccountCreation.
References
https://cloud.google.com/iam/docs/understanding-service-accounts#managing_service_account_keys
https://cloud.google.com/resource-manager/docs/organization-policy/restricting-service-accounts
Additional Information
A user-managed key cannot be created on GCP-Managed Service Accounts.