# Cis GCP Foundations 4.10

> Ensure That App Engine Applications Enforce HTTPS Connections

- Skill: `cyberstrikeus/cis-gcp-foundations-4-10` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-gcp-foundations-4-10`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-gcp-foundations-4-10/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-gcp-foundations-4-10

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# 4.10 Ensure That App Engine Applications Enforce HTTPS Connections (Manual)

## Profile Applicability

- Level 2

## Description

In order to maintain the highest level of security all connections to an application should be secure by default.

## Rationale

Insecure HTTP connections maybe subject to eavesdropping which can expose sensitive data.

## Impact

All connections to appengine will automatically be redirected to the HTTPS endpoint ensuring that all connections are secured by TLS.

## Audit

Verify that the app.yaml file controlling the application contains a line which enforces secure connections. For example:

```yaml
handlers:
  - url: /.*
    secure: always
    redirect_http_response_code: 301
    script: auto
```

Reference: https://cloud.google.com/appengine/docs/standard/python3/config/appref

## Remediation

Add a line to the app.yaml file controlling the application which enforces secure connections. For example:

```yaml
handlers:
- url: /.*
  **secure: always**
  redirect_http_response_code: 301
  script: auto
```

Reference: https://cloud.google.com/appengine/docs/standard/python3/config/appref

## Default Value

By default both HTTP and HTTP are supported.

## References

1. https://cloud.google.com/appengine/docs/standard/python3/config/appref
2. https://cloud.google.com/appengine/docs/flexible/nodejs/configuring-your-app-with-app-yaml

## CIS Controls

| Controls Version | Control                                                                       | IG 1 | IG 2 | IG 3 |
| ---------------- | ----------------------------------------------------------------------------- | ---- | ---- | ---- |
| v8               | 3.10 Encrypt Sensitive Data in Transit                                        |      | X    | X    |
| v8               | 16.11 Leverage Vetted Modules or Services for Application Security Components |      | X    | X    |
| v7               | 18.5 Use Only Standardized and Extensively Reviewed Encryption Algorithms     |      | X    | X    |