Scan all your AWS SSO accounts with Prowler

Use case

You want to run prowler scans for different AWS accounts, which AWS SSO manages.

Approach

To scan multiple AWS accounts with prowler is described here: https://docs.prowler.com/projects/prowler-open-source/en/latest/tutorials/aws/multiaccount/ Therefore, it’s necessary to have permission to assume a role in every account. This post describes how to do it with AWS SSO.

Setup

With a dockerfile, all needed tools are prepared in advance to run the scans.

Docker

The Dockerfile mainly uses the Prowler image and adds aws-sso-util.

FROM public.ecr.aws/docker/library/alpine:3.20.3 AS builder
 
RUN apk update && apk add --no-cache bash
 
FROM public.ecr.aws/prowler-cloud/prowler:4.6.1
 
COPY --from=builder /bin/bash /bin/bash
 
RUN pip install pipx && \
    pipx install aws-sso-util
    # pipx ensurepath
 
WORKDIR /workspace
 
ENTRYPOINT ["/bin/bash"]

The prowler docu for installing with docker is here: https://docs.prowler.com/projects/prowler-open-source/en/latest/#__tabbed_2_3

After creating the image with docker build -t prowler.. The container can be created with the following command.

docker run --entrypoint /bin/bash -it \
--mount type=bind,source="${PWD}/scripts",target=/workspace/scripts \
--mount type=bind,source="${PWD}/.env",target=/workspace/.env \
--mount type=bind,source="${PWD}/output",target=/workspace/output \
--name prowler \
prowler 

These are the commands to use the container again docker start -a prowler and docker exec -it prowler /bin/bash.

Initial configuration after container creation

The command for running the container mounted the folder scripts and .env file to the container.

One of the scripts is ./scripts/create-aws-config.sh which creates the file ~/.aws/config, with the SSO session values.

#!/bin/bash
 
if [ ! -f .env ] ; then
    echo "ERROR: .env file not found!"
    exit 1
else
    source .env
fi
if [ -z "$SSO_START_URL" ] ; then
    echo "ERROR: SSO_START_URL not set in .env file!"
    exit 1
fi
if [ -z "$SSO_SESSION_NAME" ] ; then
    echo "ERROR: SSO_SESSION_NAME not set in .env file!"
    exit 1
fi
if [ -z "$SSO_REGION" ] ; then
    echo "ERROR: REGION not set in .env file!"
    exit 1
fi
 
aws-sso-util configure populate \
--sso-start-url $SSO_START_URL \
--sso-region $SSO_REGION \
--region $SSO_REGION

The script needs the following env variables as file .env.

export SSO_START_URL= # https://<your-aws-account-id>.awsapps.com/start
export SSO_SESSION_NAME= # <your session name, it's just a name>
export SSO_REGION= # <your region, e.g. us-east-1>

If you run the script ./scripts/create-aws-config.sh inside the container, the tool aws-sso-util will ask for the SSO credentials.

Open the link in the browser and put in the code.

Then, allow the access.

After confirmation, the config file is created.

Prowler scans

The second script is ./scripts/run-prowler.sh which runs the prowler scan for all accounts.

#!/bin/bash
 
if [ ! -f .env ] ; then
    echo "ERROR: .env file not found!"
    exit 1
else
    source .env
fi
if [ -z "$SSO_START_URL" ] ; then
    echo "ERROR: SSO_START_URL not set in .env file!"
    exit 1
fi
if [ -z "$SSO_SESSION_NAME" ] ; then
    echo "ERROR: SSO_SESSION_NAME not set in .env file!"
    exit 1
fi
if [ -z "$SSO_REGION" ] ; then
    echo "ERROR: REGION not set in .env file!"
    exit 1
fi
 
ROLE_NAME_REGEX="^AdministratorAccess"
PROWLER_COMAND="prowler aws -i"
 
ACCOUNTS=$(aws-sso-util roles --no-header  --separator , --role-name $ROLE_NAME_REGEX --sso-start-url $SSO_START_URL --sso-region $SSO_REGION)
 
while IFS=',' read -r PROFILE ACCOUNT ROLE; do
    PROFILE=${PROFILE// /-}  # Replace spaces with hyphens in PROFILE, like aws-sso-util does
    CONFIG_PROFILE=$PROFILE.$ROLE
    echo "Profile: $PROFILE, Account: $ACCOUNT, Role: $ROLE, Config-Profile: $CONFIG_PROFILE"
    $PROWLER_COMAND --profile $CONFIG_PROFILE
done <<< "$ACCOUNTS"

The value of the variable ROLE_NAME_REGEX is a regex filter of the role name, which is connected to the AWS SSO. In this case, only the role name AdministratorAccess is used.

Some Accounts are connected with multiple roles. In this example, all Accounts have the role AdministratorAccess, so this filter works to scan all listed accounts. In another scenario, the script must be adapted to filter the right role.

The variable PROWLER_COMAND is the command to run the prowler scan.

The script ./scripts/run-prowler.sh call will look like this for every account.

If the login is expired, the script will ask for the credentials again.

The scan result is additionally saved in the folder output, which is mounted to the container. With this configuration, a JSON and a CSV file are created for every account.

This example used the Prowler quick inventory scan. Here are more examples for different scans. E.g. for compliance scans.

That’s it. Now you can scan all your AWS accounts with Prowler and AWS SSO 🥳