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# AWS API Gateway endpoints without client certificate authentication misconfiguration detected in cod

## Rule Details

|                        |                                      |
| ---------------------- | ------------------------------------ |
| Cortex AppSec Rule ID  | APPSEC2\_AWS\_51                     |
| Category - Subcategory | Public Exposure - APIs               |
| Provider               | AWS                                  |
| Severity               | LOW                                  |
| Framework              | Terraform, Terraform Plan            |
| Mapped CSPM/KSPM Rule  | 994d466e-fd3a-4a28-8c03-46f017447251 |

## Impact

This rule detects AWS API Gateway endpoints that do not use client certificate authentication. Client certificate authentication provides an additional layer of security by requiring clients to present a valid certificate issued by a trusted Certificate Authority (CA) in order to authenticate and establish a secure connection with the API Gateway endpoint.

## How to Fix

*Resource:* aws\_api\_gateway\_stage

* *Arguments:* client\_certificate\_id

To fix the issue, the `client_certificate_id` argument should be provided in the `aws_api_gateway_stage` resource. This argument allows you to specify the identifier of the ClientCertificate resource that represents the client certificate to use for authentication.

Secure code example:

In the above code example, the `aws_api_gateway_stage` resource includes the `client_certificate_id` argument which references the `aws_api_gateway_client_certificate` resource. This ensures that client certificate authentication is enabled for the API Gateway endpoint.

## By providing a valid client certificate, clients must present this certificate and undergo a mutual authentication process to establish a secure connection with the API Gateway endpoint, enhancing the overall security of the system. \[source,go]

resource "aws\_api\_gateway\_stage" "example" { stage\_name = "prod" rest\_api\_id = aws\_api\_gateway\_rest\_api.example.id deployment\_id = aws\_api\_gateway\_deployment.example.id

* client\_certificate\_id = aws\_api\_gateway\_client\_certificate.example.id }

## resource "aws\_api\_gateway\_client\_certificate" "example" { certificate\_body = filebase64("client\_certificate.pem") certificate\_chain = filebase64("certificate\_chain.pem") private\_key = filebase64("private\_key.pem") }


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