Rule: Lambda Functions Should Be Configured with a Dead-Letter Queue
This rule emphasizes the importance of configuring Lambda functions with a dead-letter queue for better incident resilience.
| Rule | Lambda functions should be configured with a dead-letter queue |
| Framework | Federal Financial Institutions Examination Council (FFIEC) |
| Severity | ✔ Medium |
Rule Description:
Lambda functions used in Federal Financial Institutions Examination Council (FFIEC) environments should be configured with a dead-letter queue. This is an important security measure to ensure the proper handling of failed invocations and mitigate potential data loss or corruption.
Reasoning:
Configuring a dead-letter queue for Lambda functions provides a safety net for handling failed invocations. It allows for easier identification and analysis of errors, as well as the preservation of the original event payload for troubleshooting purposes.
By following this rule, any failed invocations of the Lambda functions within FFIEC environments can be securely and efficiently managed.
Remediation Steps:
To configure a dead-letter queue for a Lambda function in FFIEC environments, follow these steps:
Step 1: Choose the Correct Lambda Function
Identify the specific Lambda function that needs to be configured with a dead-letter queue.
Step 2: Access Lambda Management Console
Access the AWS Management Console and navigate to the Lambda service.
Step 3: Select the Lambda Function
Find and select the previously identified Lambda function from the list.
Step 4: Configure Dead Letter Queue
On the Lambda function's configuration page, scroll down to the "Dead letter queue" section and click on "Edit".
Step 5: Enable Dead Letter Queue
Enable the dead-letter queue option by selecting the appropriate configuration.
Step 6: Specify Dead Letter Queue
Choose the SQS (Simple Queue Service) queue to be used as the dead-letter queue. If an existing queue is already available, select it; otherwise, create a new queue.
Step 7: Save the Configuration
Save the changes made to the Lambda function's configuration by clicking the appropriate button or link.
Troubleshooting Steps:
If any issues arise during the configuration of the dead-letter queue for Lambda functions, follow these troubleshooting steps:
1. Verify IAM Permissions
Ensure that the user or role trying to configure the dead-letter queue has the necessary permissions. Verify that the IAM policy associated with the user or role allows access to modify Lambda function configurations.
2. Check Queue Name and Attributes
If using an existing SQS queue, double-check that the correct queue name and attributes are provided during the configuration process. Verify that the permissions for the Lambda function to send messages to the queue are correctly set.
3. Check Queue Availability
If creating a new SQS queue, check if it is available in the specified region. Ensure that the chosen queue name is unique and does not conflict with any other existing queues.
4. Confirm Function Invocation Errors
If the dead-letter queue is not receiving failed invocations after configuration, confirm that the Lambda function is indeed encountering errors during execution. Check the function's logs and CloudWatch metrics for any indication of failed invocations.
5. Validate Event Payload
If troubleshooting a specific failed invocation, verify the content of the event payload that triggered the Lambda function. Ensure that it adheres to the expected format and does not contain any invalid or missing data.
Additional Notes:
If you are using infrastructure-as-code (IaC) tools like AWS CloudFormation or AWS CDK to manage your Lambda functions, ensure that the dead-letter queue configuration is correctly specified in your code templates.
If you have multiple Lambda functions within your FFIEC environment, it is essential to repeat the same configuration steps for each function to maintain a consistent security posture.
Regularly monitor the dead-letter queue and its associated metrics to identify any patterns of failed invocations, enabling proactive troubleshooting and optimization of your Lambda functions.