PCSE Hard Questions — 25 Difficult Questions

Question 1

A company is deploying a multi-tier application on Google Cloud. The web tier must be accessible from the internet, while the application and database tiers must only be accessible from the web tier. The security team wants to use VPC firewall rules and Cloud NAT for outbound internet access from private instances. Which architecture meets these requirements with the least operational overhead?

Accepted Answer

Place web tier in a public subnet with public IPs. Place app/db tiers in private subnets with no public IPs. Use firewall rules to allow traffic from web to app, and app to db. Configure Cloud NAT for private subnets.. Option D is correct because it uses a single VPC with separate public and private subnets, which minimizes operational overhead while meeting the security requirements. The web tier in the public subnet gets public IPs for internet access, while the app and database tiers in private subnets have no public IPs and rely on Cloud NAT for outbound internet. Firewall rules restrict traffic to only the necessary flows (web→app, app→db), and Cloud NAT provides scalable outbound connectivity without managing a proxy VM.

Answer

Use a single subnet for all tiers. Assign public IPs to all instances. Use firewall rules to restrict access between tiers. Use a proxy VM for outbound internet from app/db tiers.

Answer

Create separate VPCs for each tier. Use VPC peering to connect them. Use firewall rules to allow traffic. Use a bastion host for SSH access to app/db tiers.

Answer

Place all tiers in the same VPC. Use firewall rules to restrict access. Assign public IPs to web tier instances and private IPs to app/db tiers. Configure Cloud NAT for app/db tiers.

Question 2

A company is implementing a data retention policy for Cloud Storage buckets. They need to ensure that objects cannot be deleted before a specified retention period. Which THREE features can they use? (Choose THREE.)

Accepted Answer

Retention Policy on the bucket.. A is correct because a Retention Policy on a Cloud Storage bucket enforces a minimum retention period for all objects in the bucket. Once set, objects cannot be deleted or overwritten until the retention period expires, directly meeting the requirement to prevent deletion before a specified time.

Answer

Lifecycle rules with a Delete action.

Answer

Object versioning.

Question 3

A financial services company is migrating its on-premises application to Google Cloud. The application needs to access a Cloud SQL instance and a Cloud Storage bucket. Security requirements mandate that the application must use short-lived credentials and avoid storing long-lived service account keys. The application runs on Compute Engine. What should the Security Engineer do to meet these requirements?

Accepted Answer

Attach a service account to the Compute Engine instance with appropriate roles for Cloud SQL and Cloud Storage.. Option C is correct because attaching a service account directly to a Compute Engine instance allows the application to automatically obtain short-lived access tokens from the instance metadata server (http://169.254.169.254) for accessing Cloud SQL and Cloud Storage. This approach eliminates the need to store long-lived service account keys, meeting the security requirement for short-lived credentials.

Answer

Create a service account and use Workload Identity Federation to impersonate it.

Answer

Use Cloud Key Management Service to generate and rotate keys for the service account.

Answer

Create a service account key and store it in Cloud Secret Manager.

Question 4

A global e-commerce company must comply with GDPR and CCPA. They use BigQuery to store customer data and need to ensure that when a user requests data deletion, all copies are deleted within 30 days. Additionally, they want to minimize storage costs. Which TWO actions should they take?

Accepted Answer

Use the DDL statement to drop the table after 30 days using a scheduled query.. Option A is correct because using a DDL statement (e.g., DROP TABLE) in a scheduled query allows you to delete the entire table after exactly 30 days, ensuring all data copies (including storage and any snapshots) are removed. This directly meets the GDPR/CCPA deletion requirement while minimizing storage costs by not retaining data beyond the mandated period.

Answer

Create a Cloud Function to export the data before deletion.

Answer

Set a table retention policy of 30 days using ALTER TABLE SET OPTIONS.

Answer

Use BigQuery continuous backups with a 30-day retention.

Question 5

Refer to the exhibit. A Security Engineer runs the command to grant Alice access to view objects in a Cloud Storage bucket. Later, Alice reports she can no longer access the bucket after January 1, 2024. What is the most likely reason?

Accepted Answer

The IAM condition expired on January 1, 2024, because the timestamp condition prevented access after that date.. Option D is correct because the IAM condition attached to the binding includes a timestamp condition that expires on January 1, 2024. When the condition is no longer satisfied, the binding becomes ineffective, and Alice loses access to the bucket. This is a common use of IAM conditions to grant time-limited access.

Answer

Alice does not have the 'storage.objects.get' permission required to view objects.

Answer

The command removed Alice's existing access because it replaced all bindings.

Answer

The command failed to apply because the service account does not have permission to modify IAM policies.

Question 6

You are designing network security for a multi-region GKE cluster with Pods that need to communicate across regions over a private network. The cluster uses VPC-native mode. Which Google Cloud networking feature should you use to ensure low-latency and secure inter-region Pod-to-Pod communication without traversing the public internet?

Accepted Answer

Cloud Interconnect. Cloud Interconnect provides a dedicated, high-bandwidth, low-latency connection between your on-premises network and Google Cloud, or between Google Cloud regions, bypassing the public internet. For multi-region GKE clusters using VPC-native mode, Cloud Interconnect enables secure, private inter-region Pod-to-Pod communication by routing traffic through Google's internal backbone, ensuring minimal latency and no exposure to the public internet.

Answer

Cloud VPN with dynamic routing

Answer

Private Service Connect

Answer

VPC Flow Logs

Question 7

Your company has a VPC with multiple subnets. You have deployed a set of Compute Engine instances that must communicate with each other over TCP port 4444. The instances are tagged with 'app-tier'. You need to ensure that only these instances can communicate on this port. Which THREE of the following steps are necessary to achieve this?

Accepted Answer

Create an egress firewall rule that allows TCP 4444 from target tag 'app-tier' to source tag 'app-tier'. Option B is correct because egress firewall rules control outbound traffic from instances. By creating an egress rule allowing TCP 4444 from source tag 'app-tier' to destination tag 'app-tier', you ensure that only instances with the 'app-tier' tag can send traffic on that port to other 'app-tier' instances, while all other outbound traffic is implicitly denied by the default deny egress rule (unless overridden by a higher-priority allow rule). This restricts communication to the intended group.

Answer

Remove the default allow egress rule that allows all outbound traffic

Answer

Create a VPC firewall rule to deny all egress traffic from the VPC

Question 8

Refer to the exhibit. A security engineer runs the command to view recent decrypt operations on a Cloud KMS key. The output shows a successful decryption. However, the engineer is concerned about the exposure of the plaintext. Based on the log entry, what is the most accurate statement regarding the visibility of the decrypted plaintext?

Accepted Answer

The plaintext field is redacted by Cloud KMS, and the actual plaintext is not visible in the log entry.. Option C is correct because Cloud KMS automatically redacts the plaintext field in Cloud Audit Logs for decrypt operations. The log entry shows a successful decryption, but the actual decrypted data is never written to the logs; instead, the plaintext field is replaced with a redacted marker (e.g., `[REDACTED]`). This is a security feature to prevent sensitive data from being exposed in audit logs, even to users with access to view them.

Answer

The plaintext field is not present in the log because the service does not log it.

Answer

The plaintext field contains the base64-encoded ciphertext, and the engineer needs to decode it.

Answer

The plaintext field contains the actual decrypted data in plaintext, and the engineer should restrict access to the logs.

Question 9

A healthcare organization is migrating sensitive patient data to Google Cloud and must comply with HIPAA. They plan to use Cloud SQL for MySQL with CMEK for encryption at rest. The security team is concerned about key management and access logging. Which additional measure should be implemented to meet HIPAA audit requirements?

Accepted Answer

Enable Data Access audit logs for the Cloud SQL instance and Cloud KMS key.. Option C is correct because HIPAA audit requirements mandate that access to protected health information (PHI) and the keys protecting it must be logged. Enabling Data Access audit logs on both the Cloud SQL instance and the Cloud KMS key captures read, write, and administrative operations, providing the necessary audit trail for compliance. Without these logs, the organization cannot demonstrate who accessed the data or the encryption keys, which is a core HIPAA requirement.

Answer

Configure VPC Service Controls to restrict access to the Cloud SQL instance.

Answer

Use Cloud DLP to de-identify the data before storing it in Cloud SQL.

Answer

Store the CMEK keys in Cloud HSM to meet FIPS 140-2 Level 3 requirements.

Question 10

A financial services company runs a sensitive application on Google Kubernetes Engine (GKE) with Workload Identity enabled. Security policy requires that only pods with a specific service account can access a Cloud Storage bucket containing customer data. The bucket has uniform bucket-level access enabled. What is the correct combination of IAM bindings to achieve this?

Accepted Answer

Bind the Google service account (linked to the Kubernetes service account via Workload Identity) to the bucket IAM policy with roles/storage.objectViewer. Workload Identity links a Kubernetes service account (KSA) to a Google service account (GSA). When a pod uses that KSA, it authenticates as the linked GSA. Since the bucket has uniform bucket-level access, IAM permissions must be granted directly on the bucket resource, not at the project level. Binding the GSA to the bucket with roles/storage.objectViewer ensures only pods using that specific KSA can read the bucket.

Answer

Add the Google service account as a member of the bucket with roles/storage.objectViewer

Answer

Grant the Google service account roles/storage.objectViewer at the project level

Answer

Bind the Kubernetes service account to the bucket IAM policy with roles/storage.objectViewer

Question 11

A security engineer reviews the IAM policy for a Cloud Storage bucket as shown in the exhibit. Alice reports that she cannot upload objects to the bucket, while Bob can view objects. What is the most likely issue?

Accepted Answer

The bucket has ACLs that deny Alice upload access.. Option A is correct because Cloud Storage buckets can have both IAM policies and Access Control Lists (ACLs) applied. If the bucket's ACL explicitly denies Alice the `WRITER` or `OWNER` permission, she will be unable to upload objects even if her IAM policy grants broader roles. Bob can view objects because his IAM role (e.g., `roles/storage.objectViewer`) is not overridden by a conflicting ACL, or his ACL entry grants `READER` access.

Answer

Alice has the objectViewer role but not the objectAdmin role.

Answer

Alice does not have the storage.buckets.getIamPolicy permission.

Answer

The objectAdmin role does not include the storage.objects.create permission.

Question 12

A healthcare organization stores PHI in BigQuery tables with row-level access policies. They need to ensure that data is automatically de-identified when exported to Cloud Storage for analytics. What is the most scalable solution with minimal manual intervention?

Accepted Answer

Use BigQuery data masking to define de-identification policies, then export the masked data directly.. Option D is correct because BigQuery data masking allows you to define column-level de-identification policies that are applied automatically at query time. When you export the masked data directly using an export job, the de-identification is enforced without additional scripting or post-processing, making it the most scalable and low-maintenance solution for PHI protection.

Answer

Set up VPC Service Controls to prevent data exfiltration and rely on access controls.

Answer

Create a scheduled query in BigQuery that exports data using a view with de-identification functions.

Answer

Use Cloud DLP API to scan and de-identify the export file after it is written to Cloud Storage.

Question 13

A security engineer is configuring VPC Service Controls to protect a Google Cloud project containing sensitive data. The project uses Cloud Storage and BigQuery. The engineer wants to ensure that data cannot be exfiltrated to external IP addresses outside the perimeter, but internal users should still be able to access the data from on-premises via a VPN. Which configuration should be applied?

Accepted Answer

Add the project to a VPC Service Controls perimeter and configure an ingress rule to allow traffic from the on-premises VPN CIDR ranges. VPC Service Controls (VPC-SC) allow you to define a security perimeter around Google Cloud services like Cloud Storage and BigQuery, preventing data exfiltration to external IPs. By adding the project to a perimeter and configuring an ingress rule that permits traffic from the on-premises VPN CIDR ranges, internal users can access the data via VPN while all other external traffic is blocked. This meets the requirement of preventing exfiltration to external IPs while allowing authorized on-premises access.

Answer

Do not use VPC Service Controls; instead, rely on IAM permissions and firewall rules to control access

Answer

Create a separate perimeter that denies all traffic and apply it to the project

Answer

Add the project to a VPC Service Controls perimeter with no additional ingress rules

Question 14

A security engineer is designing a VPC Service Controls perimeter to protect a project containing sensitive data stored in Cloud Storage and BigQuery. The perimeter currently allows access from an on-premises data center via private connectivity (Cloud Interconnect). The business requires that a third-party SaaS application (outside the perimeter) be able to write data into a specific Cloud Storage bucket. Which action should the engineer take?

Accepted Answer

Create a service account for the SaaS application, grant it the Storage Object Creator role, and configure an access level that includes the service account. Then, add that access level to the perimeter's ingress policy.. Option B is correct because VPC Service Controls perimeters use ingress policies to explicitly allow access from outside the perimeter. By creating a service account for the SaaS application, granting it the Storage Object Creator role, and configuring an access level that includes that service account, the engineer can add the access level to the perimeter's ingress policy. This allows the external SaaS application to write data into the specific Cloud Storage bucket while still blocking all other external access, maintaining the security of the sensitive data.

Answer

Create a service account for the SaaS application and grant it the Storage Object Creator role; then add the service account to the perimeter's allowed identities.

Answer

Create an access level that includes the SaaS application's IP addresses and use that in the perimeter's ingress policy.

Answer

Add the SaaS application's external IP addresses to the perimeter's allowed IP ranges.

Question 15

A security engineer is designing a solution to monitor and detect anomalous IAM role usage across multiple Google Cloud projects. The engineer wants to create a centralized logging solution that captures all IAM policy changes and access attempts. Which THREE services should the engineer use together to achieve this?

Accepted Answer

BigQuery. BigQuery is correct because it serves as the centralized analytics destination for Cloud Audit Logs, enabling the security engineer to run SQL queries across IAM policy changes and access attempts from multiple Google Cloud projects. By exporting audit logs to BigQuery, you can perform complex aggregations and anomaly detection at scale, which is essential for monitoring IAM role usage across a fleet of projects.

Answer

Cloud Monitoring

Answer

Cloud Functions

Question 16

A security engineer is troubleshooting a connectivity issue between two VPCs connected via VPC Network Peering. VPC-A (project A) has a Compute Engine instance with internal IP 10.1.0.2. VPC-B (project B) has an instance with internal IP 10.2.0.2. The engineer has verified that the peering connection is active and the firewall rules allow ingress from 10.1.0.0/16. However, the instance in VPC-B cannot ping the instance in VPC-A. What is the most likely cause?

Accepted Answer

The VPC-B does not have a route to VPC-A's subnet ranges. Custom route exchange is not enabled on the peering connection.. The most likely cause is that custom route exchange is not enabled on the VPC Network Peering connection. By default, VPC peering does not exchange custom routes (including subnet routes) unless explicitly enabled. Without this, VPC-B has no route to the 10.1.0.0/16 subnet of VPC-A, so the instance in VPC-B cannot send traffic to 10.1.0.2, even though firewall rules allow ingress. The peering connection being active only means the link is established, not that routes are automatically propagated.

Answer

The VPC-A has a firewall rule that denies ICMP traffic from VPC-B.

Answer

The MTU configuration on the peering connection is set too low.

Answer

The instance in VPC-B does not have a public IP address.

Question 17

A company uses Cloud SQL for PostgreSQL with IAM database authentication. A security engineer needs to grant a user named 'analyst@example.com' the ability to run SELECT queries on the 'orders' table. The user is a member of the group 'analysts@example.com'. What is the correct combination of IAM and database permissions?

Accepted Answer

Grant the group 'analysts@example.com' the role 'roles/cloudsql.instanceUser' on the instance. In the database, create a user 'analyst@example.com' with 'cloudsqllogin' role and grant SELECT on orders to that user.. Option D is correct because IAM database authentication requires granting the IAM group the `roles/cloudsql.instanceUser` role on the instance to allow members to connect, and then creating a database user with the same name as the IAM user (not the group) with the `cloudsqllogin` role, which maps the IAM user to the database. Granting SELECT on the `orders` table to that database user then allows the IAM user to query the table.

Answer

Grant the user 'roles/cloudsql.viewer' on the project. In the database, grant SELECT on orders to 'analyst@example.com'.

Answer

Grant the user 'cloudsql.instances.connect' on the instance. In the database, create a user 'analyst@example.com' with 'cloudsqllogin' role and grant SELECT on orders to that user.

Answer

Grant the group 'roles/cloudsql.instanceUser' on the instance. In the database, create a user 'analysts@example.com' (the group) and grant SELECT on orders to that group.

Question 18

A security team is designing access controls for a multi-tenant SaaS application on Google Kubernetes Engine (GKE). Each tenant has a separate namespace. They want to ensure that a DevOps team can manage deployments across all namespaces, but cannot modify secrets in the 'tenant-alpha' namespace. Which THREE Kubernetes RBAC resources should be created? (Choose THREE)

Accepted Answer

A RoleBinding in namespace 'tenant-alpha' that binds the ClusterRole to the DevOps team.. Option A is correct because a RoleBinding in the 'tenant-alpha' namespace can bind a ClusterRole (which is a cluster-scoped resource) to the DevOps team, granting them the permissions defined in that ClusterRole within that specific namespace. Since the ClusterRole in option D explicitly excludes secrets, this RoleBinding ensures the DevOps team can manage deployments across all namespaces (via a ClusterRoleBinding) but cannot modify secrets in 'tenant-alpha'.

Answer

A ClusterRole that grants permissions to manage secrets across all namespaces.

Answer

A RoleBinding in namespace 'tenant-alpha' that binds a Role granting secret modification to the DevOps team.

Question 19

You are designing a multi-tier application with a frontend and backend. The frontend instances are in subnet A (10.0.1.0/24), and the backend instances are in subnet B (10.0.2.0/24). Both subnets are in the same VPC. You want to allow the frontend to communicate with the backend on TCP port 8080, but the backend must not be able to initiate connections to the frontend. Additionally, the backend must be able to send patches to the internet. Which set of firewall rules should you implement?

Accepted Answer

Ingress rule on backend: allow tcp:8080 from subnet A; Egress rule on backend: allow all to internet. Option B is correct because the frontend in subnet A initiates connections to the backend on TCP port 8080, so an ingress rule on the backend allowing traffic from subnet A permits this. An egress rule on the backend allowing all traffic to the internet enables patch downloads. This setup prevents the backend from initiating connections to the frontend, as no egress rule on the backend targets the frontend, and no ingress rule on the frontend allows unsolicited traffic from the backend.

Answer

Ingress rule on frontend: allow tcp:8080 from backend's service account; Egress rule on backend: allow all to internet

Answer

Ingress rule on frontend: allow tcp:8080 from subnet B; Egress rule on backend: allow all to internet

Answer

Ingress rule on backend: allow tcp:8080 from subnet A; Egress rule on frontend: deny all to internet

Question 20

A company has a Cloud Storage bucket containing sensitive data. They want to ensure that only users with specific IAM roles can access the bucket, and that access is logged for audit purposes. They also want to prevent public access. Which configuration steps should they take?

Accepted Answer

Enable uniform bucket-level access, set IAM policies, and enable Cloud Audit Logs.. Option C is correct because enabling uniform bucket-level access disables ACLs, forcing all access decisions to be made by IAM policies alone, which simplifies permission management and prevents public access. Setting IAM policies ensures only users with specific roles can access the bucket, and enabling Cloud Audit Logs captures all access requests for audit purposes. This combination meets all requirements: no public access, role-based access control, and logging.

Answer

Use IAM roles only and enable Cloud Audit Logs, but keep ACLs enabled.

Answer

Use VPC Service Controls and enable Cloud Audit Logs.

Answer

Enable fine-grained access using ACLs and enable Cloud Audit Logs.