Operational Best Practices for MAS Notice 655
Conformance packs provide a general-purpose compliance framework designed to enable you to create security, operational or cost-optimization governance checks using managed or custom AWS Config rules and AWS Config remediation actions. Conformance Packs, as sample templates, are not designed to fully ensure compliance with a specific governance or compliance standard. You are responsible for making your own assessment of whether your use of the Services meets applicable legal and regulatory requirements.
The following provides a sample mapping between the Monetary Authority of Singapore (MAS) Notice 655 – Cyber Hygiene and AWS managed Config rules. Each Config rule applies to a specific AWS resource, and relates to one or more MAS Notice 655 – Cyber Hygiene controls. A MAS Notice 655 – Cyber Hygiene control can be related to multiple Config rules. Refer to the table below for more detail and guidance related to these mappings.
| Control ID | AWS Config Rule | Guidance |
|---|---|---|
| 4.1 | This rule ensures AWS Identity and Access Management (IAM) policies are attached only to groups or roles to control access to systems and assets. Assigning privileges at the group or the role level helps to reduce opportunity for an identity to receive or retain excessive privileges. | |
| 4.1 | The credentials are audited for authorized devices, users, and processes by ensuring IAM access keys are rotated as specified by the organizational policy. Changing the access keys on a regular schedule is a security best practice. It shortens the period an access key is active and reduces the business impact if the keys are compromised. This rule requires an access key rotation value (Config Default: 90). The actual value should reflect your organization's policies. | |
| 4.1 | AWS Identity and Access Management (IAM) can help you with access permissions and authorizations by checking for IAM passwords and access keys that are not used for a specified time period. If these unused credentials are identified, you should disable and/or remove the credentials, as this may violate the principle of least privilege. This rule requires you to set a value to the maxCredentialUsageAge (Config Default: 90). The actual value should reflect your organization's policies. | |
| 4.1 | The identities and the credentials are issued, managed, and verified based on an organizational IAM password policy. They meet or exceed requirements as stated by NIST SP 800-63 and the AWS Foundational Security Best Practices standard for password strength. This rule allows you to optionally set RequireUppercaseCharacters (AWS Foundational Security Best Practices value: true), RequireLowercaseCharacters (AWS Foundational Security Best Practices value: true), RequireSymbols (AWS Foundational Security Best Practices value: true), RequireNumbers (AWS Foundational Security Best Practices value: true), MinimumPasswordLength (AWS Foundational Security Best Practices value: 14), PasswordReusePrevention (AWS Foundational Security Best Practices value: 24), and MaxPasswordAge (AWS Foundational Security Best Practices value: 90) for your IAM Password Policy. The actual values should reflect your organization's policies. | |
| 4.1 | Manage access to resources in the AWS Cloud by ensuring MFA is enabled for the root user. The root user is the most privileged user in an AWS account. The MFA adds an extra layer of protection for sign-in credentials. By requiring MFA for the root user, you can reduce the incidents of compromised AWS accounts. | |
| 4.1 | EC2 instance profiles pass an IAM role to an EC2 instance. Attaching an instance profile to your instances can assist with least privilege and permissions management. | |
| 4.1 | AWS Identity and Access Management (IAM) can help you incorporate the principles of least privilege and separation of duties with access permissions and authorizations, restricting policies from containing blocked actions on all AWS Key Management Service keys. Having more privileges than needed to complete a task may violate the principle of least privilege and separation of duties. This rule allows you to set the blockedActionsPatterns parameter. (AWS Foundational Security Best Practices value: kms:Decrypt, kms:ReEncryptFrom). The actual values should reflect your organization's policies | |
| 4.1 | Ensure an AWS Identity and Access Management (IAM) user, IAM role or IAM group does not have an inline policy to allow blocked actions on all AWS Key Management Service keys. AWS recommends to use managed policies instead of inline policies. The managed policies allow reusability, versioning, rolling back, and delegating permissions management. This rule allows you to set the blockedActionsPatterns parameter. (AWS Foundational Security Best Practices value: kms:Decrypt, kms:ReEncryptFrom). The actual values should reflect your organization's policies. | |
| 4.1 | Access to systems and assets can be controlled by checking that the root user does not have access keys attached to their AWS Identity and Access Management (IAM) role. Ensure that the root access keys are deleted. Instead, create and use role-based AWS accounts to help to incorporate the principle of least functionality. | |
| 4.1 | Manage access to resources in the AWS Cloud by ensuring hardware MFA is enabled for the root user. The root user is the most privileged user in an AWS account. The MFA adds an extra layer of protection for sign-in credentials. By requiring MFA for the root user, you can reduce the incidents of compromised AWS accounts. | |
| 4.1 | Manage access to resources in the AWS Cloud by ensuring that MFA is enabled for all AWS Identity and Access Management (IAM) users that have a console password. MFA adds an extra layer of protection on top of sign-in credentials. By requiring MFA for users, you can reduce incidents of compromised accounts and keep sensitive data from being accessed by unauthorized users. | |
| 4.1 | Enable this rule to restrict access to resources in the AWS Cloud. This rule ensures multi-factor authentication (MFA) is enabled for all users. MFA adds an extra layer of protection on top of sign-in credentials. Reduce the incidents of compromised accounts by requiring MFA for users. | |
| 4.1 | The access permissions and authorizations can be managed and incorporated with the principles of least privilege and separation of duties, by enabling Kerberos for Amazon EMR clusters. In Kerberos, the services and the users that need to authenticate are known as principals. The principals exist within a Kerberos realm. Within the realm, a Kerberos server is known as the key distribution center (KDC). It provides a means for the principals to authenticate. The KDC authenticates by issuing tickets for authentication. The KDC maintains a database of the principals within its realm, their passwords, and other administrative information about each principal. | |
| 4.1 | AWS Identity and Access Management (IAM) can help you restrict access permissions and authorizations, by ensuring users are members of at least one group. Allowing users more privileges than needed to complete a task may violate the principle of least privilege and separation of duties. | |
| 4.1 | AWS Identity and Access Management (IAM) can help you incorporate the principles of least privilege and separation of duties with access permissions and authorizations, restricting policies from containing "Effect": "Allow" with "Action": "*" over "Resource": "*". Allowing users to have more privileges than needed to complete a task may violate the principle of least privilege and separation of duties. | |
| 4.1 | Ensure an AWS Identity and Access Management (IAM) user, IAM role or IAM group does not have an inline policy to control access to systems and assets. AWS recommends to use managed policies instead of inline policies. The managed policies allow reusability, versioning and rolling back, and delegating permissions management. | |
| 4.1 | AWS Identity and Access Management (IAM) can help you incorporate the principles of least privilege and separation of duties with access permissions and authorizations, by ensuring that IAM groups have at least one user. Placing users in groups based on their associated permissions or job function is one way to incorporate least privilege. | |
| 4.1 | This rule ensures AWS Secrets Manager secrets have rotation enabled. Rotating secrets on a regular schedule can shorten the period a secret is active, and potentially reduce the business impact if the secret is compromised. | |
| 4.1 | This rule ensures that AWS Secrets Manager secrets have rotated successfully according to the rotation schedule. Rotating secrets on a regular schedule can shorten the period that a secret is active, and potentially reduce the business impact if it is compromised. | |
| 4.1 | Ensure IAM Actions are restricted to only those actions that are needed. Allowing users to have more privileges than needed to complete a task may violate the principle of least privilege and separation of duties. | |
| 4.2 | An inventory of the software platforms and applications within the organization is possible by managing Amazon Elastic Compute Cloud (Amazon EC2) instances with AWS Systems Manager. Use AWS Systems Manager to provide detailed system configurations, operating system patch levels, services name and type, software installations, application name, publisher and version, and other details about your environment. | |
| 4.2 | Enable this rule to help with identification and documentation of Amazon Elastic Compute Cloud (Amazon EC2) vulnerabilities. The rule checks if Amazon EC2 instance patch compliance in AWS Systems Manager as required by your organization's policies and procedures. | |
| 4.2 | Use AWS Systems Manager Associations to help with inventory of software platforms and applications within an organization. AWS Systems Manager assigns a configuration state to your managed instances and allows you to set baselines of operating system patch levels, software installations, application configurations, and other details about your environment. | |
| 4.2 | This rule ensures that Amazon Redshift clusters have the preferred settings for your organization. Specifically, that they have preferred maintenance windows and automated snapshot retention periods for the database. This rule requires you to set the allowVersionUpgrade. The default is true. It also lets you optionally set the preferredMaintenanceWindow (the default is sat:16:00-sat:16:30), and the automatedSnapshotRetentionPeriod (the default is 1). The actual values should reflect your organization's policies. | |
| 4.2 | Ensure the Instance Metadata Service Version 2 (IMDSv2) method is enabled to help protect access and control of Amazon Elastic Compute Cloud (Amazon EC2) instance metadata. The IMDSv2 method uses session-based controls. With IMDSv2, controls can be implemented to restrict changes to instance metadata. | |
| 4.2 | Enabling managed platform updates for an Amazon Elastic Beanstalk environment ensures that the latest available platform fixes, updates, and features for the environment are installed. Keeping up to date with patch installation is a best practice in securing systems. | |
| 4.2 | Enable automatic minor version upgrades on your Amazon Relational Database Service (RDS) instances to ensure the latest minor version updates to the Relational Database Management System (RDBMS) are installed, which may include security patches and bug fixes. | |
| 4.2 | Amazon Elastic Container Repository (ECR) image scanning assists in identifying software vulnerabilities in your container images. Enabling image scanning on ECR repositories adds a layer of verification for the integrity and safety of the images being stored. | |
| 4.3 | An inventory of the software platforms and applications within the organization is possible by managing Amazon Elastic Compute Cloud (Amazon EC2) instances with AWS Systems Manager. Use AWS Systems Manager to provide detailed system configurations, operating system patch levels, services name and type, software installations, application name, publisher and version, and other details about your environment. | |
| 4.3 | AWS Security Hub helps to monitor unauthorized personnel, connections, devices, and software. AWS Security Hub aggregates, organizes, and prioritizes the security alerts, or findings, from multiple AWS services. Some such services are Amazon Security Hub, Amazon Inspector, Amazon Macie, AWS Identity and Access Management (IAM) Access Analyzer, and AWS Firewall Manager, and AWS Partner solutions. | |
| 4.3 | Use AWS Systems Manager Associations to help with inventory of software platforms and applications within an organization. AWS Systems Manager assigns a configuration state to your managed instances and allows you to set baselines of operating system patch levels, software installations, application configurations, and other details about your environment. | |
| 4.3 | Centralized management of AWS accounts within AWS Organizations helps to ensure that accounts are compliant. The lack of centralized account governance may lead to inconsistent account configurations, which may expose resources and sensitive data. | |
| 4.4 | Ensure AWS WAF is enabled on Elastic Load Balancers (ELB) to help protect web applications. A WAF helps to protect your web applications or APIs against common web exploits. These web exploits may affect availability, compromise security, or consume excessive resources within your environment. | |
| 4.4 | Manage access to the AWS Cloud by ensuring DMS replication instances cannot be publicly accessed. DMS replication instances can contain sensitive information and access control is required for such accounts. | |
| 4.4 | Manage access to the AWS Cloud by ensuring EBS snapshots are not publicly restorable. EBS volume snapshots can contain sensitive information and access control is required for such accounts. | |
| 4.4 | Manage access to the AWS Cloud by ensuring Amazon Elastic Compute Cloud (Amazon EC2) instances cannot be publicly accessed. Amazon EC2 instances can contain sensitive information and access control is required for such accounts. | |
| 4.4 | This rule ensures the security groups are attached to an Amazon Elastic Compute Cloud (Amazon EC2) instance or to an ENI. This rule helps monitoring unused security groups in the inventory and the management of your environment. | |
| 4.4 | Manage access to the AWS Cloud by ensuring Amazon OpenSearch Service (OpenSearch Service) Domains are within an Amazon Virtual Private Cloud (Amazon VPC). An OpenSearch Service domain within an Amazon VPC enables secure communication between OpenSearch Service and other services within the Amazon VPC without the need for an internet gateway, NAT device, or VPN connection. | |
| 4.4 | Manage access to the AWS Cloud by ensuring Amazon EMR cluster master nodes cannot be publicly accessed. Amazon EMR cluster master nodes can contain sensitive information and access control is required for such accounts. | |
| 4.4 | Amazon GuardDuty can help to monitor and detect potential cybersecurity events by using threat intelligence feeds. These include lists of malicious IPs and machine learning to identify unexpected, unauthorized, and malicious activity within your AWS Cloud environment. | |
| 4.4 | Amazon Elastic Compute Cloud (Amazon EC2) Security Groups can help manage network access by providing stateful filtering of ingress and egress network traffic to AWS resources. Not allowing ingress (or remote) traffic from 0.0.0.0/0 to port 22 on your resources help you restricting remote access. | |
| 4.4 | Deploy Amazon Elastic Compute Cloud (Amazon EC2) instances within an Amazon Virtual Private Cloud (Amazon VPC) to enable secure communication between an instance and other services within the amazon VPC, without requiring an internet gateway, NAT device, or VPN connection. All traffic remains securely within the AWS Cloud. Because of their logical isolation, domains that reside within an Amazon VPC have an extra layer of security when compared to domains that use public endpoints. Assign Amazon EC2 instances to an Amazon VPC to properly manage access. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring that internet gateways are only attached to authorized Amazon Virtual Private Cloud (Amazon VPC). Internet gateways allow bi-directional internet access to and from the Amazon VPC that can potentially lead to unauthorized access to Amazon VPC resources. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring AWS Lambda functions cannot be publicly accessed. Public access can potentially lead to degradation of availability of resources. | |
| 4.4 | Deploy AWS Lambda functions within an Amazon Virtual Private Cloud (Amazon VPC) for a secure communication between a function and other services within the Amazon VPC. With this configuration, there is no requirement for an internet gateway, NAT device, or VPN connection. All the traffic remains securely within the AWS Cloud. Because of their logical isolation, domains that reside within an Amazon VPC have an extra layer of security when compared to domains that use public endpoints. To properly manage access, AWS Lambda functions should be assigned to a VPC. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring that Amazon Relational Database Service (Amazon RDS) instances are not public. Amazon RDS database instances can contain sensitive information, and principles and access control is required for such accounts. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring that Amazon Relational Database Service (Amazon RDS) instances are not public. Amazon RDS database instances can contain sensitive information and principles and access control is required for such accounts. | |
| 4.4 | Ensure your AWS WAF has a rule that is not empty. A rule with no conditions could result in unintended behavior. | |
| 4.4 | Ensure your AWS WAF has a rule group that is not empty. A rule group that is empty could result in unintended behavior. | |
| 4.4 | A Web ACL attached to an AWS WAF can contain a collection of rules and rule groups to inspect and control web requests. If a Web ACL is empty, the web traffic passes without being detected or acted upon by the WAF. | |
| 4.4 | An AWS Network Firewall policy defines how your firewall monitors and handles traffic in an Amazon VPC. You configure stateless and stateful rule groups to filter packets and traffic flows. Defaulting to a Pass action may allow unintended traffic. | |
| 4.4 | An AWS Network Firewall policy defines how your firewall monitors and handles traffic in an Amazon VPC. You configure stateless and stateful rule groups to filter packets and traffic flows. Defaulting to a Pass action may allow unintended traffic. | |
| 4.4 | An AWS Network Firewall policy defines how your firewall monitors and handles traffic in an Amazon VPC. You configure stateless and stateful rule groups to filter packets and traffic flows, and you define default traffic handling. | |
| 4.4 | An AWS Network Firewall rule group contains rules that define how your firewall processes traffic in your VPC. An empty stateless rule group when present in a firewall policy does not process traffic. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring that Amazon Redshift clusters are not public. Amazon Redshift clusters can contain sensitive information and principles and access control is required for such accounts. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring common ports are restricted on Amazon Elastic Compute Cloud (Amazon EC2) security groups. Not restricting access to ports to trusted sources can lead to attacks against the availability, integrity and confidentiality of systems. This rule allows you to optionally set blockedPort1 - blockedPort5 parameters (Config Defaults: 20,21,3389,3306,4333). The actual values should reflect your organization's policies. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring that Amazon Simple Storage Service (Amazon S3) buckets cannot be publicly accessed. This rule helps keeping sensitive data safe from unauthorized remote users by preventing public access. This rule allows you to optionally set the ignorePublicAcls (Config Default: True), blockPublicPolicy (Config Default: True), blockPublicAcls (Config Default: True), and restrictPublicBuckets parameters (Config Default: True). The actual values should reflect your organization's policies. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring that Amazon SageMaker notebooks do not allow direct internet access. By preventing direct internet access, you can keep sensitive data from being accessed by unauthorized users. | |
| 4.4 | Amazon Elastic Compute Cloud (Amazon EC2) security groups can help in the management of network access by providing stateful filtering of ingress and egress network traffic to AWS resources. Restricting all the traffic on the default security group helps in restricting remote access to your AWS resources. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring common ports are restricted on Amazon Elastic Compute Cloud (Amazon EC2) Security Groups. Not restricting access on ports to trusted sources can lead to attacks against the availability, integrity and confidentiality of systems. By restricting access to resources within a security group from the internet (0.0.0.0/0) remote access can be controlled to internal systems. | |
| 4.4 | Manage access to resources in the AWS Cloud by only allowing authorized users, processes, and devices access to Amazon Simple Storage Service (Amazon S3) buckets. The management of access should be consistent with the classification of the data. | |
| 4.4 | Manage access to resources in the AWS Cloud by only allowing authorized users, processes, and devices access to Amazon Simple Storage Service (Amazon S3) buckets. The management of access should be consistent with the classification of the data. | |
| 4.4 | Ensure Amazon EC2 route tables do not have unrestricted routes to an internet gateway. Removing or limiting the access to the internet for workloads within Amazon VPCs can reduce unintended access within your environment. | |
| 4.4 | Manage access to resources in the AWS Cloud by ensuring that Amazon Simple Storage Service (Amazon S3) buckets cannot be publicly accessed. This rule helps keeping sensitive data safe from unauthorized remote users by preventing public access at the bucket level. | |
| 4.4 | Manage access to the AWS Cloud by ensuring Amazon Virtual Private Cloud (VPC) subnets are not automatically assigned a public IP address. Amazon Elastic Compute Cloud (EC2) instances that are launched into subnets that have this attribute enabled have a public IP address assigned to their primary network interface. | |
| 4.4 | If you configure your Network Interfaces with a public IP address, then the associated resources to those Network Interfaces are reachable from the internet. EC2 resources should not be publicly accessible, as this may allow unintended access to your applications or servers. | |
| 4.4 | Enhanced VPC routing forces all COPY and UNLOAD traffic between the cluster and data repositories to go through your Amazon VPC. You can then use VPC features such as security groups and network access control lists to secure network traffic. You can also use VPC flow logs to monitor network traffic. | |
| 4.4 | Ensure AWS Systems Manager (SSM) documents are not public, as this may allow unintended access to your SSM documents. A public SSM document can expose information about your account, resources and internal processes. | |
| 4.4 | AWS WAF enables you to configure a set of rules (called a web access control list (web ACL)) that allow, block, or count web requests based on customizable web security rules and conditions that you define. Ensure your Amazon API Gateway stage is associated with a WAF Web ACL to protect it from malicious attacks | |
| 4.4 | Manage access to the AWS Cloud by ensuring Amazon OpenSearch Service domains are within an Amazon Virtual Private Cloud (Amazon VPC). An Amazon OpenSearch Service domain within an Amazon VPC enables secure communication between Amazon OpenSearch Service and other services within the Amazon VPC without the need for an internet gateway, NAT device, or VPN connection. | |
| 4.5 | An inventory of the software platforms and applications within the organization is possible by managing Amazon Elastic Compute Cloud (Amazon EC2) instances with AWS Systems Manager. Use AWS Systems Manager to provide detailed system configurations, operating system patch levels, services name and type, software installations, application name, publisher and version, and other details about your environment. | |
| 4.5 | Enable this rule to help with identification and documentation of Amazon Elastic Compute Cloud (Amazon EC2) vulnerabilities. The rule checks if Amazon EC2 instance patch compliance in AWS Systems Manager as required by your organization's policies and procedures. | |
| 4.5 | Use AWS Systems Manager Associations to help with inventory of software platforms and applications within an organization. AWS Systems Manager assigns a configuration state to your managed instances and allows you to set baselines of operating system patch levels, software installations, application configurations, and other details about your environment. | |
| 4.5 | Amazon GuardDuty can help to monitor and detect potential cybersecurity events by using threat intelligence feeds. These include lists of malicious IPs and machine learning to identify unexpected, unauthorized, and malicious activity within your AWS Cloud environment. | |
| 4.6 | The identities and the credentials are issued, managed, and verified based on an organizational IAM password policy. They meet or exceed requirements as stated by NIST SP 800-63 and the AWS Foundational Security Best Practices standard for password strength. This rule allows you to optionally set RequireUppercaseCharacters (AWS Foundational Security Best Practices value: true), RequireLowercaseCharacters (AWS Foundational Security Best Practices value: true), RequireSymbols (AWS Foundational Security Best Practices value: true), RequireNumbers (AWS Foundational Security Best Practices value: true), MinimumPasswordLength (AWS Foundational Security Best Practices value: 14), PasswordReusePrevention (AWS Foundational Security Best Practices value: 24), and MaxPasswordAge (AWS Foundational Security Best Practices value: 90) for your IAM Password Policy. The actual values should reflect your organization's policies. | |
| 4.6 | Manage access to resources in the AWS Cloud by ensuring MFA is enabled for the root user. The root user is the most privileged user in an AWS account. The MFA adds an extra layer of protection for sign-in credentials. By requiring MFA for the root user, you can reduce the incidents of compromised AWS accounts. | |
| 4.6 | Access to systems and assets can be controlled by checking that the root user does not have access keys attached to their AWS Identity and Access Management (IAM) role. Ensure that the root access keys are deleted. Instead, create and use role-based AWS accounts to help to incorporate the principle of least functionality. | |
| 4.6 | Manage access to resources in the AWS Cloud by ensuring hardware MFA is enabled for the root user. The root user is the most privileged user in an AWS account. The MFA adds an extra layer of protection for sign-in credentials. By requiring MFA for the root user, you can reduce the incidents of compromised AWS accounts. | |
| 4.6 | Manage access to resources in the AWS Cloud by ensuring that MFA is enabled for all AWS Identity and Access Management (IAM) users that have a console password. MFA adds an extra layer of protection on top of sign-in credentials. By requiring MFA for users, you can reduce incidents of compromised accounts and keep sensitive data from being accessed by unauthorized users. | |
| 4.6 | Enable this rule to restrict access to resources in the AWS Cloud. This rule ensures multi-factor authentication (MFA) is enabled for all users. MFA adds an extra layer of protection on top of sign-in credentials. Reduce the incidents of compromised accounts by requiring MFA for users. |
Template
The template is available on GitHub: Operational Best Practices for MAS Notice 655
