Rule: Lambda Functions in a VPC
This rule emphasizes the necessity of placing Lambda functions within a VPC for enhanced security measures.
| Rule | Lambda functions should be in a VPC |
| Framework | FedRAMP Low Revision 4 |
| Severity | ✔ Low |
Rule Description
Lambda functions should be configured to run within a Virtual Private Cloud (VPC) for FedRAMP Low Revision 4 compliance. A VPC provides an isolated network environment for Lambda functions, ensuring enhanced network security and control.
Troubleshooting Steps
1. Verify VPC Configuration
Check if the Lambda function is correctly associated with a VPC. You can do this by navigating to the AWS Lambda console and selecting the Lambda function in question. Under the "VPC" section, ensure that a VPC and respective subnets are properly assigned.
2. Confirm VPC Access
Ensure that the Lambda execution role has the necessary permissions to access the VPC and subnets. The role should include the appropriate AWS Identity and Access Management (IAM) policies granting VPC and subnet permissions.
3. Validate Security Group Settings
Verify that the security groups associated with the Lambda function and the VPC allow the required inbound and outbound traffic. Double-check the rules specified in the security groups and adjust them if necessary.
4. Check for IP Address Conflicts
Ensure that there are no IP address conflicts within the VPC or subnet range assigned to the Lambda function. Conflicts can lead to network connectivity issues and should be resolved by adjusting the IP settings accordingly.
Necessary Codes
There are no specific codes provided for this rule. However, certain Lambda configuration settings may need to be adjusted to comply with the VPC requirement. Refer to the following guidelines for remediation.
Remediation Steps
1. Associating Lambda Function with a VPC
- 1.Open the AWS Management Console and navigate to the Lambda service.
- 2.Select the Lambda function that needs to be configured to run within a VPC.
- 3.In the function details page, click on the "Configuration" tab.
- 4.Scroll down to the "Network" section and click on the "Edit" button.
- 5.Choose the desired VPC from the "VPC" dropdown menu.
- 6.Select one or more subnets within the chosen VPC.
- 7.Click on the "Save" button to apply the changes.
2. Adjusting Lambda Execution Role Permissions
- 1.Access the AWS IAM console.
- 2.Locate the IAM role associated with the Lambda function.
- 3.Click on the role name to view its details.
- 4.In the role summary page, click on the "Attach policies" button.
- 5.Search for the necessary policies related to VPC and subnet access.
- 6.Select the relevant policies and click on the "Attach policy" button to grant the required permissions.
3. Configuring Security Group Rules
- 1.Open the Amazon VPC console.
- 2.Navigate to the "Security Groups" section.
- 3.Locate the security group associated with the Lambda function's VPC.
- 4.Select the security group and click on the "Inbound Rules" or "Outbound Rules" tab.
- 5.Modify the rules as per your application's requirements, ensuring that necessary ports and protocols are allowed.
- 6.Save the changes to update the security group configuration.
4. Resolving IP Address Conflicts
In case of IP address conflicts within the VPC or subnet range:
- 1.Evaluate the IP addresses assigned to resources within the VPC.
- 2.Identify conflicting IP addresses and the associated resources.
- 3.Adjust the IP configurations of the conflicting resources to resolve the conflicts.
- 4.Update the IP settings of the Lambda function's VPC and subnets accordingly.
Conclusion
Adhering to the mentioned remediation steps will enable Lambda functions to operate within a VPC, ensuring compliance with the FedRAMP Low Revision 4 policy. Verify the VPC configuration, establish proper VPC access permissions, adjust security group rules, and resolve IP address conflicts if encountered.