> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/appsec-rules/iac-security/storage/appsec-aws-173.md).

# AWS Lambda encryption settings environmental variable is not set properly misconfiguration detected

## Rule Details

|                        |                                                       |
| ---------------------- | ----------------------------------------------------- |
| Cortex AppSec Rule ID  | APPSEC\_AWS\_173                                      |
| Category - Subcategory | Storage - Encryption                                  |
| Provider               | AWS                                                   |
| Severity               | LOW                                                   |
| Framework              | CloudFormation, Serverless, Terraform, Terraform Plan |

## Impact

This rule checks the encryption settings for environment variables in AWS Lambda functions. It's essential to use a KMS key for encrypting environment variables to protect sensitive data. If environment variables are provided, a KMS key must be specified. This rule checks whether the `kms_key_arn` is set when environment variables are used in a Lambda function.

## How to Fix

To fix this issue, ensure that when environment variables are specified in the `AWS::Lambda::Function` or `AWS::Serverless::Function` resource, the `KmsKeyArn` property is also set to a valid KMS key ARN.

Example for AWS Lambda Function:

## Example for AWS Serverless Function: \[source,go]

{ "Resources": { "MyLambdaFunction": { "Type": "AWS::Lambda::Function", "Properties": { ... "Environment": { "Variables": { "EXAMPLE\_VAR": "example-value" } },

* "KmsKeyArn": "arn:aws:kms:us-west-2:123456789012:key/example-key-arn", ... } } } }

***

Resources: MyServerlessFunction: Type: AWS::Serverless::Function Properties: ... Environment: Variables: EXAMPLE\_VAR: example-value

* KmsKeyArn: arn:aws:kms:us-west-2:123456789012:key/example-key-arn

***


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