Privilege Escalation: Dormant Service Account Granted Sensitive Role

This document describes a threat finding type in Security Command Center. Threat findings are generated by threat detectors when they detect a potential threat in your cloud resources. For a full list of available threat findings, see Threat findings index.

Overview

A sensitive IAM role was granted to a dormant user-managed service account. In this context, a service account is considered dormant if it has been inactive for more than 180 days.

How to respond

To respond to this finding, do the following:

Step 1: Review finding details

  1. Open the Privilege Escalation: Dormant Service Account Granted Sensitive Role finding, as directed in Reviewing findings.

  2. In the finding details, on the Summary tab, note the values of following fields.

    Under What was detected:

    • Principal email: the user who conducted the granting action
    • Offending access grants.Principal name: The dormant service account that received the sensitive role
    • Offending access grants.Role granted: The sensitive IAM role that are assigned

    Under Affected resource:

    • Resource display name: the organization, folder or project in which the sensitive IAM role was granted to the dormant service account.

Step 2: Research attack and response methods

  1. Use service account tools, like Activity Analyzer, to investigate the activity of the dormant service account.
  2. Contact the owner of the Principal email field. Confirm whether the legitimate owner conducted the action.

Step 3: Check logs

  1. On the Summary tab of the finding details panel, under the Related links click the Cloud Logging URI link to open the Logs Explorer.

Step 4: Implement your response

The following response plan might be appropriate for this finding, but might also impact operations. Carefully evaluate the information you gather in your investigation to determine the best way to resolve findings.

  • Contact the owner of the project where the action was taken.
  • Remove the access of the owner of the Principal email if it is compromised.
  • Remove the newly assigned sensitive IAM role from the dormant service account.
  • Consider deleting the potentially compromised service account and rotate and delete all service account access keys for the potentially compromised project. After deletion, resources that use the service account for authentication lose access. Before proceeding, your security team should identify all impacted resources and work with resource owners to ensure business continuity.
  • Work with your security team to identify unfamiliar resources, including Compute Engine instances, snapshots, service accounts, and IAM users. Delete resources not created with authorized accounts.
  • Respond to any notifications from Cloud Customer Care.
  • To limit who can create service accounts, use the Organization Policy Service.
  • To identify and fix overly permissive roles, use IAM recommender.

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