# Serverless / FaaS Security Cheat Sheet — 6. Secrets Management

> Fetch secrets at runtime from a vault or caching extension — not from platform-level function configuration (e.g.

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-owasp-407b457ed184c02cee07>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:11.457484+00:00`
- Tags: `reference-seed`, `owasp`, `cheatsheets`, `serverless`, `faas`, `security`, `cheat`, `sheet`, `secrets`, `management`

## Provenance

- Source: <https://github.com/OWASP/CheatSheetSeries/blob/07111ee754e832e335377ac64fd0f8f848d9029c/cheatsheets/Serverless_FaaS_Security_Cheat_Sheet.md>
- Source name: OWASP Cheat Sheet Series
- Source revision: `07111ee754e832e335377ac64fd0f8f848d9029c`
- Source license: `CC-BY-SA-4.0`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

Fetch secrets at runtime from a vault or caching extension — not from platform-level function configuration (e.g. Lambda Environment Variables). Use ephemeral credentials (STS, workload identity federation). Rotate secrets automatically.

AWS Lambda Secret Fetch (Python via Parameters and Secrets Extension)

Note: Ensure that the AWS Lambda Parameters and Secrets Extension is added and enabled for your function (for example, as a Lambda layer). Otherwise, will not be available and requests to it will fail.

Bounded code example (external data; do not execute automatically):
```python
import os
import json
import urllib.request
import urllib.parse

def get_secret(secret_name):
    """
    Retrieves a secret using the AWS Lambda Extension local endpoint.
    This method is faster and more cost-effective due to local caching.
    """
    # The extension provides a local HTTP endpoint on port 2773
    encoded_name = urllib.parse.quote_plus(secret_name)

    secrets_extension_endpoint = (
        f"http://localhost:2773/secretsmanager/get?secretId={encoded_name}"
    )

    # Authenticate using the identity token provided by the Lambda environment.
    # Fail fast if the token is missing to avoid confusing 4xx errors.
    session_token = os.environ.get("AWS_SESSION_TOKEN")
    if not session_token:
        raise RuntimeError(
            "Missing AWS_SESSION_TOKEN required for "
            "Parameters and Secrets Extension authentication."
        )

    headers = {
```

Attribution: Adapted from OWASP Cheat Sheet Series under CC-BY-SA-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.