Cloud in Red Teaming

Introduction

In the evolving landscape of cybersecurity, the cloud has become a fundamental component of modern IT infrastructures. However, as organizations migrate their services and data to cloud platforms, the attack surface expands, creating new opportunities and challenges for attackers and defenders alike. Cloud red teaming involves simulating advanced persistent threats (APTs) in cloud environments to identify vulnerabilities, test defenses, and improve security posture. Despite its critical importance, cloud red teaming is often overlooked in real-world scenarios. This document aims to elucidate the role of cloud red teaming, its methods, techniques, and the impact it can have on organizations using major cloud service providers like AWS, Azure, and GCP.

The Role of Cloud Red Teaming

Cloud red teaming plays a pivotal role in assessing the security of cloud environments. It helps organizations understand how attackers might exploit cloud-specific vulnerabilities, misconfigurations, and weaknesses. The goal is to emulate real-world attack scenarios to identify gaps in security controls, incident response capabilities, and overall cloud security strategies.

Key Objectives:

• Identify and exploit vulnerabilities in cloud configurations and deployments.

• Test the effectiveness of cloud-specific security controls and incident response processes.

• Simulate lateral movement and privilege escalation within cloud environments.

• Assess the security of cloud-native services and applications.

Impact of Cloud Red Teaming

Enhanced Security Posture: By identifying and addressing vulnerabilities, organizations can significantly enhance their cloud security posture. This proactive approach helps in mitigating risks before they can be exploited by malicious actors.

Improved Incident Response: Testing incident response capabilities in cloud environments ensures that organizations are prepared to detect, respond to, and recover from cloud-based attacks.

Regulatory Compliance: Many industries have stringent regulatory requirements for data protection and security. Cloud red teaming helps organizations meet these compliance standards by validating the effectiveness of their security controls.

Cost Savings: Identifying and remediating vulnerabilities early can save organizations from the financial repercussions of data breaches, including fines, legal fees, and reputational damage.

Methods and Techniques

Cloud red teaming involves a combination of traditional penetration testing techniques and cloud-specific strategies. Here are some common methods and techniques:

Reconnaissance: Gathering information about the target cloud environment, including publicly accessible resources, IAM roles, policies, and configurations.

Tools:

• AWS: awscli, CloudMapper

• Azure: Az PowerShell, Azure CLI

• GCP: gcloud

Exploiting Misconfigurations: Identifying and exploiting misconfigurations in cloud resources such as S3 buckets, storage accounts, IAM policies, and network settings.

Example:

• AWS: Exploiting an S3 bucket with public read/write permissions to upload malicious files.

• Azure: Accessing blob storage with misconfigured access controls.

• GCP: Exploiting misconfigured IAM policies to gain unauthorized access to resources.

Privilege Escalation: Elevating privileges within the cloud environment to gain administrative access.

Example:

• AWS: Using a misconfigured IAM role to escalate privileges.

• Azure: Exploiting vulnerable managed identities or misconfigured role assignments.

• GCP: Leveraging service account keys for privilege escalation.

Lateral Movement: Moving laterally within the cloud environment to access additional resources and data.

Example:

• AWS: Using compromised EC2 instances to access other instances or resources in the same VPC.

• Azure: Exploiting Virtual Network (VNet) peering to move between VNets.

• GCP: Utilizing network connectivity between different projects or regions.

Data Exfiltration: Extracting sensitive data from cloud environments.

Example:

• AWS: Downloading sensitive data from S3 buckets or RDS instances.

• Azure: Exfiltrating data from SQL databases or storage accounts.

• GCP: Accessing and downloading data from Cloud Storage or BigQuery.

Cloud-Specific Considerations

AWS (Amazon Web Services)

Key Services:

• IAM: Manage user access and encryption keys.

• EC2: Virtual servers in the cloud.

• S3: Scalable object storage.

• RDS: Managed relational database service.

• Lambda: Run code without provisioning servers.

Common Techniques:

• Exploiting IAM roles and policies.

• S3 bucket enumeration and exploitation.

• Privilege escalation via Lambda functions.

• Lateral movement through VPC peering.

Azure (Microsoft Azure)

Key Services:

• Azure AD: Identity and access management.

• VMs: Virtual machines in the cloud.

• Blob Storage: Scalable storage for unstructured data.

• SQL Database: Managed relational database service.

• Azure Functions: Serverless compute service.

Common Techniques:

• Exploiting Azure AD misconfigurations.

• Blob storage enumeration and exploitation.

• Privilege escalation through managed identities.

• Lateral movement using VNet peering.

GCP (Google Cloud Platform)

Key Services:

• IAM: Manage permissions and roles.

• Compute Engine: Virtual machines in the cloud.

• Cloud Storage: Scalable object storage.

• BigQuery: Fully managed data warehouse.

• Cloud Functions: Event-driven serverless compute.

Common Techniques:

• Exploiting IAM role bindings.

• Cloud Storage bucket enumeration and exploitation.

• Privilege escalation via service account keys.

• Lateral movement using network connectivity between projects.

Useful Learning resources: We should have leaked AWS and Azure Credentials (ID and KEY) to launch attacks mentioned in the below links:

PayloadsAllTheThings/Cloud - Azure Pentest.md at master · swisskyrepo/PayloadsAllTheThingsGitHub

PayloadsAllTheThings/Cloud - AWS Pentest.md at master · swisskyrepo/PayloadsAllTheThingsGitHub

Awesome tool other than Aws-cli and Azure cli:

GitHub - RhinoSecurityLabs/pacu: The AWS exploitation framework, designed for testing the security of Amazon Web Services environments.GitHub

S3 Bucket attack help:

PayloadsAllTheThings/AWS Amazon Bucket S3/README.md at master · swisskyrepo/PayloadsAllTheThingsGitHub

Case Study: S3 Bucket Compromise

During a real-world red teaming engagement, we discovered a writable S3 bucket that was publicly accessible. This misconfiguration allowed anyone with the correct URL to upload or download files from the bucket. Here's how the attack unfolded and the subsequent impact:

Initial Discovery: Using the awscli tool, we enumerated the S3 buckets associated with the target organization. The command used for this was:

aws s3 ls

We identified several buckets and began probing their permissions. To test for public write access, we attempted to upload a test file:

aws s3 cp testfile.txt s3://vulnerable-bucket/

The upload was successful, confirming that the bucket was writable by unauthorized users.

Impact: By having write access to this bucket, we could upload malicious files, overwrite existing files, or introduce unauthorized content, potentially leading to various attack scenarios such as:

• Malware Distribution: Uploading malicious files that could be downloaded and executed by unsuspecting users.

• Data Tampering: Modifying existing files, leading to data integrity issues.

• Credential Harvesting: Placing phishing pages or scripts that capture sensitive information.

The organization was immediately alerted to this critical vulnerability. They responded by correcting the bucket's permissions, ensuring that only authorized users had access.

What was the takeaway from this lesson for Client's Information Security Team:

Remediation Steps: The organization took the following steps to remediate the issue:

Restricting Bucket Policies: They modified the S3 bucket policies to restrict public write access. This was achieved using the following command:

aws s3api put-bucket-policy --bucket vulnerable-bucket --policy file://restrictive-policy.json

The restrictive-policy.json file contained:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Deny",
      "Principal": "*",
      "Action": "s3:PutObject",
      "Resource": "arn:aws:s3:::vulnerable-bucket/*",
      "Condition": {
        "StringNotEquals": {
          "aws:PrincipalAccount": "123456789012"
        }
      }
    }
  ]
}

Auditing Other Buckets: They audited all other S3 buckets to ensure no other misconfigurations were present.

Monitoring and Alerts: Implementing monitoring and alerting for changes to S3 bucket policies and access patterns using AWS CloudTrail and AWS Config.

This case study highlights the importance of thoroughly auditing cloud configurations and permissions during red teaming exercises. Misconfigured resources, like writable S3 buckets, can lead to significant security breaches if left unchecked.

Detection and Response Strategies

To effectively detect and respond to cloud-based attacks, organizations should implement comprehensive monitoring and incident response strategies. Key tools and practices include:

CloudTrail for AWS: Enable AWS CloudTrail to log all API calls and activities within the AWS environment. Regularly review these logs for suspicious activities, such as unauthorized access or changes to critical resources.

Command to enable CloudTrail:

aws cloudtrail create-trail --name MyTrail --s3-bucket-name my-trail-bucket
aws cloudtrail start-logging --name MyTrail

• Azure Security Center: Use Azure Security Center to gain visibility into security posture, manage security policies, and detect threats across Azure resources.

• GCP Security Command Center: Utilize GCP Security Command Center to identify and manage cloud security risks across GCP projects.

Best Practices for Cloud Security

Principle of Least Privilege: Apply the principle of least privilege to IAM roles and permissions, ensuring users and services have only the access they need to perform their tasks.

Regular Audits: Conduct regular security audits and reviews of cloud configurations and policies to identify and remediate vulnerabilities promptly.

Encryption: Ensure data is encrypted both at rest and in transit to protect sensitive information from unauthorized access.

Multi-Factor Authentication (MFA): Enforce MFA for all user accounts to add an extra layer of security against unauthorized access.

Common Challenges and Solutions:

Challenge: Misconfigurations Solution: Regularly use automated tools to scan for and remediate misconfigurations. Implement configuration management policies and tools like AWS Config, Azure Policy, and GCP Config Validator.

Challenge: Lack of Visibility Solution: Implement comprehensive logging and monitoring solutions to gain visibility into all cloud activities. Use centralized logging systems and SIEM solutions for real-time analysis and alerts.

Challenge: Complex IAM Policies Solution: Simplify IAM policies by grouping users with similar access needs and applying policies at the group level. Regularly review and update IAM policies to ensure they align with current security requirements.

Tools and Frameworks

AWS Security Hub: A comprehensive view of high-priority security alerts and compliance status across AWS accounts.

Azure Sentinel: A scalable, cloud-native SIEM for intelligent security analytics and threat intelligence across the enterprise.

Google Cloud Security Command Center: A security and risk management platform for visibility into security risks and policy compliance.

Emerging Threats

Container Security: With the rise of containerized applications, securing container environments such as Docker and Kubernetes is crucial. Focus on securing container images, runtime security, and orchestration layers.

Serverless Security: As serverless architectures grow in popularity, ensure the security of serverless functions, manage permissions carefully, and monitor for unusual activities.

Zero Trust Architecture: Adopt a zero-trust approach to security, where no entity is trusted by default, and continuous verification is required for access.

Collaboration with Blue Teams

Effective cloud security requires close collaboration between red and blue teams. Red teamers provide insights into potential vulnerabilities and attack vectors, while blue teams use this information to strengthen defenses and improve detection and response capabilities.

Joint Exercises: Conduct joint red and blue team exercises to simulate attacks and improve defensive strategies. This collaboration fosters a proactive security culture and enhances overall security posture.

Legal and Compliance Considerations

Data Privacy Regulations: Ensure compliance with data privacy regulations such as GDPR, CCPA, and HIPAA when conducting red teaming exercises. Obtain necessary permissions and avoid accessing or exfiltrating real sensitive data.

Cloud Provider Policies: Familiarize yourself with the acceptable use policies and guidelines of cloud service providers to avoid violating terms of service during red teaming activities.

Conclusion

Cloud red teaming is a vital component of modern security assessments, enabling organizations to identify and mitigate vulnerabilities within their cloud environments. By understanding the unique attack vectors and techniques associated with cloud platforms like AWS, Azure, and GCP, red teamers can provide valuable insights into the effectiveness of cloud security controls and incident response capabilities.

Despite its importance, cloud red teaming is often overlooked in real-world scenarios. Organizations must prioritize these assessments to stay ahead of evolving threats and ensure the security of their cloud infrastructure. Through comprehensive cloud red teaming exercises, organizations can achieve enhanced security posture, improved incident response, regulatory compliance, and significant cost savings.

In summary, cloud red teaming should be an integral part of any organization's security strategy, providing a realistic evaluation of their cloud defenses and helping them prepare for the sophisticated attacks of tomorrow.