> 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/iam/appsec-aws-258.md).

# AWS Lambda function URL AuthType set to NONE misconfiguration detected in code

## Rule Details

|                        |                                      |
| ---------------------- | ------------------------------------ |
| Cortex AppSec Rule ID  | APPSEC\_AWS\_258                     |
| Category - Subcategory | Public Exposure - APIs               |
| Provider               | AWS                                  |
| Severity               | MEDIUM                               |
| Framework              | CloudFormation, Terraform            |
| Mapped CSPM/KSPM Rule  | 92a3fce2-0875-49da-af5c-71c3366100bf |

## Impact

This rule identifies AWS Lambda functions which have function URL AuthType set to NONE. AuthType determines how Lambda authenticates or authorises requests to your function URL. When AuthType is set to NONE, Lambda doesn't perform any authentication before invoking your function. It is highly recommended to set AuthType to AWS\_IAM for Lambda function URL to authenticate via AWS IAM.

## How to Fix

To fix this issue, ensure that the `AuthType` property in the `AWS::Lambda::Url` resource is set to a value other than `None`. For example, you can set it to `AWS_IAM` to enforce IAM-based authentication.

## Example: \[source,go]

{ "Resources": { "MyLambdaFunctionURL": { "Type": "AWS::Lambda::Url", "Properties": {

* "AuthType": None,
* "AuthType": "AWS\_IAM", ... } } } }

***

Resources: MyLambdaFunctionURL: Type: AWS::Lambda::Url Properties:

* AuthType: None
* AuthType: AWS\_IAM ...

***


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