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lacework-global-294

note

This rule has been changed to manual, see Manual Policies for CIS GCP 1.3.0 for details.

Profile Applicability​

• Level 2

Description​

Best practices recommend enforcing the principle of 'Separation of Duties' while assigning service-account related roles to users.

Rationale​

The built-in/predefined IAM role Service Account admin allows the user/identity to create, delete, and manage service account(s). The built-in/predefined IAM role Service Account User allows the user/identity (with adequate privileges on Compute and App Engine) to assign service account(s) to Apps/Compute Instances.

Separation of duties is the concept of ensuring that one individual does not have all necessary permissions to be able to complete a malicious action. In Cloud IAM - service accounts, this could be an action such as using a service account to access resources that user should not normally have access to.

Separation of duties is a business control typically used in larger organizations, meant to help avoid security or privacy incidents and errors. It is considered best practice.

No user should have Service Account Admin and Service Account User roles assigned at the same time.

Impact​

The removed role should be assigned to a different user based on business needs.

Audit​

From Console:

  1. Go to IAM & Admin/IAM using https://console.cloud.google.com/iam-admin/iam.

  2. Ensure no member has the roles Service Account Admin and Service account User assigned together.

From Command Line:

  1. List all users and role assignments:
gcloud projects get-iam-policy [Project_ID] --format json | \
 jq -r '[
 (["Service_Account_Admin_and_User"] | (., map(length*"-"))), 
 (
 [
 .bindings[] | 
 select(.role == "roles/iam.serviceAccountAdmin" or .role == "roles/iam.serviceAccountUser").members[]
 ] | 
 group_by(.) | 
 map({User: ., Count: length}) | 
 .[] | 
 select(.Count == 2).User | 
 unique
 )
 ] | 
 .[] | 
 @tsv'
  1. All common users listed under Service_Account_Admin_and_User are assigned both the roles/iam.serviceAccountAdmin and roles/iam.serviceAccountUser roles.

Remediation​

From Console:

  1. Go to Identity and Access Management (IAM) & Admin/IAM using: https://console.cloud.google.com/iam-admin/iam.

  2. For any member having both Service Account Admin and Service account User roles granted/assigned, click the Delete Bin icon to remove either role from the member. Use business requirements to guide removal of a role.

References​

https://cloud.google.com/iam/docs/service-accounts
https://cloud.google.com/iam/docs/understanding-roles
https://cloud.google.com/iam/docs/granting-roles-to-service-accounts

Additional Information​

Users granted with Owner (roles/owner) and Editor (roles/editor) have privileges equivalent to Service Account Admin and Service Account User. To avoid the misuse, grant Owner and Editor roles to very limited users and Use of these primitive privileges should be minimal. Separate recommendations address these requirements.

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