CCSK Domain 2: Governance and Enterprise Risk Management

Governance and risk management principles remain the same, but there are changes to the risk picture as well as available controls in the cloud. We need in particular take into account the following:

  • Cloud risk trade-offs and tools
  • Effects of service and deployment models
  • Risk management in the cloud
  • Tools of cloud governance

A key aspect to remember when deploying services or data to the cloud is that even if security controls are delegated to a third-party, the responsibility for corporate governance cannot be delegated; it remains within the cloud consumer organization.

Cloud providers aim to streamline and standardize their offerings as much as possible to achieve economies of scale. This is different from a dedicated third-party provider where contractual terms can often be negotiated. This means that governance frameworks should not treat cloud providers with the same approach as those dedicated service providers allowing for custom governance structures to be agreed on.

Responsibilities and mechanisms for governance is regulated in the contract. If a governance need is not described in the contract, there exists a governance gap. This does not mean that the provider should be excluded directly, but it does mean that the consumer should consider how that governance gap can be closed.

Moving to the cloud transfers a lot of the governance and risk management from technical controls to contractual controls.

Cloud governance tools

The key tools of governance in the cloud are contracts, assessments and reporting.

Contracts are the primary tools for extending governance into a third party such as a cloud provider. For public clouds this would typically mean the terms and conditions of the provider. They are the guarantee of a given service level, and also describes requirements for governance support through audits.

Supplier assessments are important as governance tools, especially during provider selection. Performing regular assessments can discover if changes to the offerings of the cloud provider has changed the governance situation, in particular with regard to any governance gaps.

Compliance reporting includes audit reports. They may also include automatically generated compliance data in a dashboard, such as patch level status on software, or some other defined KPI. Audit reports may be internal reports but most often these are made by an accredited third party. Common compliance frameworks are provided by ISO 27017, ISO 38500, COBIT.

Risk management

Enterprise risk management (ERM) in the cloud is based on the shared responsibility model. The provider will take responsibility for certain risk controls, whereas the consumer is responsible for others. Where the split is depends on the service model.

The division of responsibilities should be clearly regulated in the contract. Lack of such regulation can lead to hidden implementation gaps, leaving services vulnerable to abuse.

Service models

IaaS mostly resembles traditional IT as most controls remain under direct management of the cloud consumer. Thus, policies and controls do to a large degree remain under control of the cloud consumer too. There is one primary change and that is the orchestration/management plane. Managing the risk of the management plane becomes a core governance and risk management activity – basically moving responsibilities from on-prem activities to the management plane.

SaaS providers vary greatly in competence and the tools offered for compliance management. It is often possible to negotiate custom contracts with smaller SaaS providers, whereas the more mature or bigger players will have more standardized contracts but also more tools appropriate to governance needs of the enterprise. The SaaS model can be less transparent than desired, and establishing an acceptable contract is important in order to have good control over governance and risk management.

Public cloud providers often allow for less negotiation than private cloud. Hybrid and community governance can easily become complicated because the opinions of several parties will have to be weighed against each other.

Risk trade-offs

Using cloud services will typically result in more trust put in third-parties and less direct access to security controls. Whether this increases or decreases the overall risk level depends on the threat model, as well as political risk.

The key issue is that governance is changed from internal policy and auditing to contracts and audit reports; it is a less hands-on approach and can result in lower transparency and trust in the governance model.

CSA recommendations

  • Identify the shared responsibilities. Use accepted standards to build a cloud governance framework.
  • Understand and manage how contracts affect risk and governance. Consider alternative controls if a contract leaves governance gaps and cannot be changed.
  • Develop a process with criteria for provider selection. Re-assessments should be regular, and preferably automated.
  • Align risks to risk tolerances per asset as different assets may have different tolerance levels.

#2cents

Let us start with the contract side: most cloud deployments will be in a public cloud, and our ability to negotiate custom contracts will be very limited, or non-existing. What we will have to play with is the control options in the management plane.

The first thing we should perhaps take note of, is not really cloud related. We need to have a regulatory compliance matrix in order to make sure our governance framework and risk management processes actually will help us achieve compliance and acceptable risk levels. One practical way to set up a regulatory compliance matrix is to map applicable regulations and governacne requirements to the governance tools we have at our disposal to see if the tools can help achieve compliance.

Regulatory source Contractual impact Supplier assessments Audits Configuration management
GDPR Data processing agreement Security requirements GDPR compliance Data processing acitvities audits Data retention Backups Discoverability Encryption
Customer SLA SLA guarantees
Uptime reporting
ISO 27001
Certifications Audit reports for certifications Extension of company policies to management plane

Based on the regulatory compliance matrix, a more detailed governance matrix can be developed based on applicable guidance. Then governance and risk management gaps can be identified, and closing plans created.

Traditionally cloud deployments have been seen as higher risk than on-premise deployments due to less hands-on risk controls. For many organizations the use of cloud services with proper monitoring will lead to better security because many organizations have insufficient security controls and logging in their on-premise tools. There are thus situations where a shift from hands-on to contractual controls is a good thing for security. One could probably claim that this is the case for most cloud consumers.

One aspect that is critical to security is planning of incident response. To some degree the ability to do incidence response on cloud deployments depends on configurations set in the management plane; especially the use of logging and alerting functionality. It should also be clarified up front where the shared responsibility model puts the responsibility for performing incident response actions throughout all phases (preparation, identification, containment, eradication, recovery and lessons learned).

The best way to take cloud into account in risk management and governance is to make sure policies, procedures and standards cover cloud, and that cloud is not seen as an “add-on” to on-premise services. Only integrated governance systems will achieve transparency and managed regulatory compliance.

CCSK Domain 1: Cloud Computing Concepts and Architecture

Recently I participated in a one-day class on the contents required for the “Certificate of Cloud Security Knowledge” held by Peter HJ van Eijk in Trondheim as part of the conference Sikkerhet og Sårbarhet 2019 (translates from Norwegian to: Security and Vulnerability 2019). The one-day workshop was interesting and the instructor was good at creating interactive discussions – making it much better than the typical PowerPoint overdose of commmercial professional training sessions. There is a certification exam that I have not yet taken, and I decided I should document my notes on my blog; perhaps others can find some use for them too.

The CCSK exam closely follows a document made by the Cloud Security Alliance (CSA) called “CSA Security Guidance for Critical Areas of Focus in Cloud Computing v4.0” – a document you can download for free from the CSA webpage. They also lean on ENISA’s “Cloud Computing Risk Assessment”, which is also a free download.

Cloud computing isn’t about who owns the compute resources (someone else’s computer) – it is about providing scale and cost benefits through rapid elasticity, self-service, shared resource pools and a shared security responsibility model.

The way I’ll do these blog posts is that I’ll first share my notes, and then give a quick comment on what the whole thing means from my point of view (which may not really be that relevant to the CCSK exam if you came here for a shortcut to that).

Introduction to D1 (Cloud Concepts and Architecture)

Domain 1 contains 4 sections:  

  • Defining cloud computing 
  • The cloud logical model 
  • Cloud conceptual, architectural and reference model 
  • Cloud security and compliance scope, responsibilities and models 

NIST definition of cloud computing: a model for ensuring ubiquitous, convenient, on-demand network access to a shared pool for configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction. 

A Cloud User is the person or organization requesting computational resources. The Cloud Provider is the person or organization offering the resources. 

Key techniques to create a cloud:  

  • Abstraction: we abstract resources from the underlying infrastructure to create resource pools  
  • Orchestration: coordination of delivering resources out of the pool on demand.  

Clouds are multitenant by nature. Consumers are segregated and isolated but share resource pools.  

Cloud computing models 

The foundation model of cloud computing of the CSA is the NIST model. A more in-depth model used as a reference model is taken from ISO/IEC.  The guidance talks mostly about the NIST model and doesn’t dive into the ISO/IEC model, which probably is sufficient for most definition needs.

Cloud computing has 5 charcteristics:

  1. Shared resource pool (compute resources in a pool that consumers can pull from)
  2. Rapid elasticity (can scale up and down quickly)
  3. Broad network access
  4. On-demand self-service (management plane, API’s)
  5. Measured service (pay-as-you-go)

Cloud computing has 3 service models

  • Software as a Service (SaaS): like Cybehave or Salesforce
  • Platform as a Service (PaaS): like WordPress or AWS Elastic Beanstalk
  • Infrastructure as a Service (IaaS): like VM’s running in Google Cloud

Cloud computing has 4 deployment models:

  • Public Cloud: pool shared by anyone
  • Private Cloud: pool shared within an organization
  • Hybrid Cloud: connection between two clouds, commonly used when an on-prem datacenter connects to a public cloud
  • Community Cloud: pool shared by a community, for example insurance companies that have formed some form of consortium

Models for discussing cloud security

The CSA document discusses multiple model type in a somewhat incoherent manner. The types of models it mentions can be categorized as follows:

  • Conceptual models: descriptions to explain concepts, such as the logic model from CSA.  
  • Controls models: like CCM 
  • Reference architectures: templates for implementing security controls 
  • Design patterns: solutions to particular problems 

The document also outlines a simple cloud security process model 

  • Identify security and compliance requirements, and existing controls 
  • Select provider, service and deployment models 
  • Define the architecture 
  • Assess the security controls 
  • Identify control gaps 
  • Design and implement controls to fill gaps 
  • Manage changes over time 

The CSA logic model

This model explains 4 “layers” of a cloud enviornment and introduces some “funny words”:

  • Infrastructure: the core components in computing infrastructure, such as servers, storage and networks 
  • Metastructure: protocols and mechanisms providing connections between infrastructure and the other layers 
  • Infostructure: The data and information (database records, file storage, etc) 
  • Applistructure: The applications deployed in the cloud and the underlying applications used ot build them. 

The key difference between traditional IT and cloud is the metastructure. Cloud metastructure contains the management plane components.  

Another key feature of cloud is that each layer tends to double. For example infrastructure is managed by the cloud provider, but the cloud consumer will establish a virtual infrastructure that will also need ot be managed (at least in the case of IaaS). 

Cloud security scope and responsibilities 

The responsibility for security domains maps to the access the different stakeholders have to each layer in the architecture stack.  

  • SaaS: cloud provider is responsible for perimeter, logging, and application security and the consumer may only have access to provision users and manage entitlemnets 
  • PaaS: the provider is typically responsible for platform security and the consumer is responsible for the security of the solutions deployed on the platform. Configuring the offered security features is often left to the consumer.  
  • IaaS: cloud provider is responsible for hypervisors, host OS, hardware and facilities, consumer for guest OS and up in the stack.  

Shared responsibility model leaves us with two focus areas:  

  • Cloud providers should clearly document internal security management and security controls available to consumers.  
  • Consumers should create a responsibility matrix to make sure controls are followed up by one of the parties 

Two compliance tools exist from the CSA and are recommended for mapping security controls:  

  • The Consensus Assessment Initiative Questionnaire (CAIQ) 
  • The Cloud Controls Matrix (CCM) 

#2cents

This domain is introductory and provides some terminology for discussing cloud computing. The key aspects from a risk management point of view are:

  • Cloud creates new risks that need to be managed, especially as it introduces more companies involved in maintaining security of the full stack compared to a full in-house managed stack. Requirements, contracts and audits become important tools.
  • The NIST model is more or less universally used in cloud discussions in practice. The service models are known to most IT practitioners, at least on the operations side.
  • The CSA guidance correctly designates the “metastructure” as the new kid on the block. The practical incarnation of this is API’s and console access (e.g. gcloud at API level and Google Cloud Console on “management plane” level). From a security point of view this means that maintaining security of local control libraries becomes very important, as well as identity and access management for the control plane in general.

In addition to the “who does what” problem that can occur with a shared security model, the self-service and fast-scaling properties of cloud computing often lead to “new and shiny” being pushed faster than security is aware of. An often overlooked part of “pushing security left” is that we also need to push both knowledge and accountability together with the ability to access the management plane (or parts of it through API’s or the cloud management console).