Terraform security scanning tools - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Identify the primary purpose of Terraform security scanning tools

What is the main goal of using security scanning tools with Terraform configurations?

A To optimize the cost of cloud resources after deployment

B To automatically deploy infrastructure without manual approval

C To detect potential security risks and misconfigurations before deployment

D To monitor real-time network traffic of deployed resources

💡 Hint

Think about what security scanning tools check in code before it runs.

Terraform security scanning tools analyze the code to find security issues or risky settings before the infrastructure is created. This helps prevent vulnerabilities early.

❓ service_behavior

intermediate

Behavior of Terraform Sentinel policy when a security rule fails

In Terraform Cloud, if a Sentinel policy designed to block insecure resource configurations fails during a plan, what happens?

A The Terraform plan is blocked and cannot be applied until the issue is fixed

B The Terraform plan is applied but logs a warning message

C The Terraform plan ignores the Sentinel policy and proceeds normally

D The Terraform plan automatically fixes the insecure configuration

💡 Hint

Sentinel policies enforce rules before changes happen.

Sentinel policies act as gatekeepers. If a policy fails, Terraform Cloud blocks the plan from applying to prevent insecure changes.

❓ Configuration

advanced

Detecting insecure AWS S3 bucket configuration with tfsec

Given the following Terraform snippet, which tfsec command output correctly identifies a public S3 bucket risk?

Terraform

resource "aws_s3_bucket" "example" {
  bucket = "my-public-bucket"
  acl    = "public-read"
}

A INFO: aws-s3-bucket-versioning: Bucket 'my-public-bucket' does not have versioning enabled

B ERROR: aws-s3-enable-bucket-encryption: Bucket 'my-public-bucket' does not have encryption enabled

C WARNING: aws-s3-enable-bucket-encryption: Bucket 'my-public-bucket' has public read ACL, which is insecure

D WARNING: aws-s3-public-read-prohibited: Bucket 'my-public-bucket' has public read ACL, which is insecure

💡 Hint

Look for the tfsec rule that warns about public read ACLs.

tfsec warns with 'aws-s3-public-read-prohibited' when a bucket has a public read ACL, indicating a security risk.

❓ Architecture

advanced

Best architecture to integrate Terraform security scanning in CI/CD

Which architecture best integrates Terraform security scanning tools into a CI/CD pipeline to ensure security checks before deployment?

A Include security scanning as a step after deployment to production

B Add security scanning as a mandatory step after Terraform plan and before apply in the CI/CD pipeline

C Run security scanning tools only on completed Terraform apply in production

D Run security scanning tools as a pre-commit hook on developer machines only

💡 Hint

Think about when security checks should block unsafe changes.

Integrating security scanning after plan and before apply in CI/CD ensures unsafe configurations are caught before deployment.

❓ security

expert

Identifying the cause of a Terraform security scan failure with Checkov

Given this Terraform resource snippet, which Checkov rule failure explains why the scan fails?

resource "aws_security_group" "example" {
  name        = "allow_ssh"
  description = "Allow SSH inbound"

  ingress {
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

A CKV_AWS_21: Security group allows ingress from 0.0.0.0/0 on port 22 (SSH) which is insecure

B CKV_AWS_52: Security group missing egress rules, blocking all outbound traffic

C CKV_AWS_70: Security group has no tags defined for resource tracking

D CKV_AWS_99: Security group uses deprecated protocol type

💡 Hint

Which rule warns about open SSH access from anywhere?

Checkov rule CKV_AWS_21 flags security groups that allow SSH access from all IPs (0.0.0.0/0) as a security risk.

Practice

1. What is the main purpose of Terraform security scanning tools like tfsec?

easy

A. To monitor cloud resource usage costs

B. To deploy Terraform infrastructure automatically

C. To write Terraform code faster with autocomplete

D. To find security risks in Terraform code before deployment

Solution

1. Step 1: Understand Terraform security scanning tools

   These tools analyze Terraform code to detect potential security issues early.

2. Step 2: Compare options with tool purpose

   Only To find security risks in Terraform code before deployment matches the purpose of finding security risks before deployment.

3. Final Answer:

   To find security risks in Terraform code before deployment -> Option D

4. Quick Check:

   Security scanning = find risks [OK]

Hint: Security tools find risks in code before cloud setup [OK]

Common Mistakes:

• Confusing scanning tools with deployment tools
• Thinking scanning tools write code
• Assuming scanning tools track costs

2. Which command correctly runs tfsec to scan your Terraform project in the current folder?

easy

A. tfsec scan terraform

B. terraform scan

C. tfsec .

D. terraform tfsec run

Solution

1. Step 1: Recall tfsec usage syntax

   The correct way to run tfsec is by specifying the folder, commonly the current folder with a dot.

2. Step 2: Match command to syntax

   Only tfsec . correctly runs tfsec on the current directory.

3. Final Answer:

   tfsec . -> Option C

4. Quick Check:

   Run tfsec with folder path, dot means current folder [OK]

Hint: Run tfsec with dot for current folder scan [OK]

Common Mistakes:

• Using terraform commands instead of tfsec
• Adding extra words like 'scan' or 'run'
• Not specifying folder or using wrong syntax

3. Given this tfsec output snippet:

Warning: AWS S3 bucket is publicly accessible
  File: main.tf:12
  Severity: HIGH

What does this output mean?

medium

A. The S3 bucket in main.tf line 12 allows public access, which is risky

B. The S3 bucket is encrypted and secure

C. The S3 bucket is missing from the Terraform code

D. The S3 bucket is private and safe

Solution

1. Step 1: Interpret tfsec warning message

   The warning says the S3 bucket is publicly accessible, which means anyone can access it.

2. Step 2: Understand security implication

   Public access to S3 buckets is a high-risk security issue, so this is a warning to fix it.

3. Final Answer:

   The S3 bucket in main.tf line 12 allows public access, which is risky -> Option A

4. Quick Check:

   Public access warning = risky bucket [OK]

Hint: Warnings show risky settings like public access [OK]

Common Mistakes:

• Thinking warning means bucket is secure
• Confusing missing resource with public access
• Ignoring file and line number details

4. You ran tfsec . but got an error: command not found: tfsec. What is the most likely fix?

medium

A. Run terraform init first

B. Install tfsec on your system and ensure it's in your PATH

C. Change directory to the Terraform root folder

D. Update Terraform version to latest

Solution

1. Step 1: Understand the error meaning

   The error means the system cannot find the tfsec command, so it is not installed or not accessible.

2. Step 2: Fix by installing tfsec and adding to PATH

   Installing tfsec and ensuring the command is available in the system PATH fixes this error.

3. Final Answer:

   Install tfsec on your system and ensure it's in your PATH -> Option B

4. Quick Check:

   Command not found = install tool [OK]

Hint: Install tfsec if command not found error appears [OK]

Common Mistakes:

• Running terraform commands instead of installing tfsec
• Assuming directory change fixes command not found
• Updating Terraform version unrelated to tfsec error

5. You want to automate security scanning in your CI pipeline using tfsec. Which approach best ensures security issues are caught before deployment?

hard

A. Run tfsec . before Terraform apply and fail pipeline on warnings

B. Run tfsec . after Terraform apply to check deployed resources

C. Run terraform plan and ignore tfsec

D. Run tfsec . only on production branch merges

Solution

1. Step 1: Understand when to run security scans

   Security scanning should happen before deployment to catch issues early.

2. Step 2: Choose pipeline behavior to enforce security

   Failing the pipeline on warnings ensures no risky code is deployed.

3. Step 3: Evaluate other options

   Running after apply is too late; ignoring tfsec misses risks; scanning only production branch misses early detection.

4. Final Answer:

   Run tfsec . before Terraform apply and fail pipeline on warnings -> Option A

5. Quick Check:

   Scan before deploy and fail on warnings [OK]

Hint: Scan before deploy and fail on warnings to block risks [OK]

Common Mistakes:

• Running scans after deployment
• Ignoring tfsec in pipeline
• Scanning only production branch too late