# AWS - MSK Enum

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## Amazon MSK

**Amazon Managed Streaming for Apache Kafka (Amazon MSK)** is a service that is fully managed, facilitating the development and execution of applications processing streaming data through **Apache Kafka**. Control-plane operations, including creation, update, and deletion of **clusters**, are offered by Amazon MSK. The service permits the utilization of Apache Kafka **data-plane operations**, encompassing data production and consumption. It operates on **open-source versions of Apache Kafka**, ensuring compatibility with existing applications, tooling, and plugins from both partners and the **Apache Kafka community**, eliminating the need for alterations in the application code.

In terms of reliability, Amazon MSK is designed to **automatically detect and recover from prevalent cluster failure scenarios**, ensuring that producer and consumer applications persist in their data writing and reading activities with minimal disruption. Moreover, it aims to optimize data replication processes by attempting to **reuse the storage of replaced brokers**, thereby minimizing the volume of data that needs to be replicated by Apache Kafka.

### **Types**

There are 2 types of Kafka clusters that AWS allows to create: Provisioned and Serverless.

From the point of view of an attacker you need to know that:

- **Serverless cannot be directly public** (it can only run in a VPN without any publicly exposed IP). However, **Provisioned** can be configured to get a **public IP** (by default it doesn't) and configure the **security group** to **expose** the relevant ports.
- **Serverless** **only support IAM** as authentication method. **Provisioned** support SASL/SCRAM (**password**) authentication, **IAM** authentication, AWS **Certificate** Manager (ACM) authentication and **Unauthenticated** access.
  - Note that it's not possible to expose publicly a Provisioned Kafka if unauthenticated access is enabled

### Enumeration

```bash
#Get clusters
aws kafka list-clusters
aws kafka list-clusters-v2

# Check the supported authentication
aws kafka list-clusters |  jq -r ".ClusterInfoList[].ClientAuthentication"

# Get Zookeeper endpoints
aws kafka list-clusters | jq -r ".ClusterInfoList[].ZookeeperConnectString, .ClusterInfoList[].ZookeeperConnectStringTls"

# Get nodes and node enspoints
aws kafka kafka list-nodes --cluster-arn <cluster-arn>
aws kafka kafka list-nodes --cluster-arn <cluster-arn> | jq -r ".NodeInfoList[].BrokerNodeInfo.Endpoints" # Get endpoints

# Get used kafka configs
aws kafka list-configurations #Get Kafka config file
aws kafka describe-configuration --arn <config-arn> # Get version of config
aws kafka describe-configuration-revision --arn <config-arn> --revision <version> # Get content of config version

# If using SCRAN authentication, get used AWS secret name (not secret value)
aws kafka list-scram-secrets --cluster-arn <cluster-arn>
```

### Kafka IAM Access (in serverless)

```bash
# Guide from https://docs.aws.amazon.com/msk/latest/developerguide/create-serverless-cluster.html
# Download Kafka
wget https://archive.apache.org/dist/kafka/2.8.1/kafka_2.12-2.8.1.tgz
tar -xzf kafka_2.12-2.8.1.tgz

# In kafka_2.12-2.8.1/libs download the MSK IAM JAR file.
cd kafka_2.12-2.8.1/libs
wget https://github.com/aws/aws-msk-iam-auth/releases/download/v1.1.1/aws-msk-iam-auth-1.1.1-all.jar

# Create file client.properties in kafka_2.12-2.8.1/bin
security.protocol=SASL_SSL
sasl.mechanism=AWS_MSK_IAM
sasl.jaas.config=software.amazon.msk.auth.iam.IAMLoginModule required;
sasl.client.callback.handler.class=software.amazon.msk.auth.iam.IAMClientCallbackHandler

# Export endpoints address
export BS=boot-ok2ngypz.c2.kafka-serverless.us-east-1.amazonaws.com:9098
## Make sure you will be able to access the port 9098 from the EC2 instance (check VPS, subnets and SG)

# Create a topic called msk-serverless-tutorial
kafka_2.12-2.8.1/bin/kafka-topics.sh --bootstrap-server $BS --command-config client.properties --create --topic msk-serverless-tutorial --partitions 6

# Send message of every new line
kafka_2.12-2.8.1/bin/kafka-console-producer.sh --broker-list $BS --producer.config client.properties --topic msk-serverless-tutorial

# Read messages
kafka_2.12-2.8.1/bin/kafka-console-consumer.sh --bootstrap-server $BS --consumer.config client.properties --topic msk-serverless-tutorial --from-beginning
```

### Privesc

{{#ref}}
../aws-privilege-escalation/aws-msk-privesc/README.md
{{#endref}}

### Unauthenticated Access

{{#ref}}
../aws-unauthenticated-enum-access/aws-msk-unauthenticated-enum/README.md
{{#endref}}

### Persistence

If you are going to **have access to the VPC** where a Provisioned Kafka is, you could **enable unauthorised access**, if **SASL/SCRAM authentication**, **read** the password from the secret, give some **other controlled user IAM permissions** (if IAM or serverless used) or persist with **certificates**.

## References

- [https://docs.aws.amazon.com/msk/latest/developerguide/what-is-msk.html](https://docs.aws.amazon.com/msk/latest/developerguide/what-is-msk.html)

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