CMMC – Cybersecurity Risk Management
This blog post “CMMC – Cybersecurity Risk Management’’ is the eighth in a series on Cybersecurity Maturity Model Certification (CMMC) – a US Department of Defense (DoD) initiative that imposes requirements on contractors and subcontractors to help safeguard information within the US defense supply chain.
In this post we look at risk management and how you can achieve a higher degree of maturity in your approach to risk assessments and mitigation activity using a combination of people, processes and technology.
Security risk assessments
An important aspect of your information security programme is to implement a clear and unambiguous security risk assessment methodology and ensure that clear boundaries between domains and systems are in place, so people know what is required. Security risk assessments, unlike business risk assessments, consider security threats, vulnerabilities, likelihood and impact together to calculate the overall risk rating. Security controls can influence vulnerability and impact to help reduce that rating. Threats are hard to change, as is the likelihood of that threat acting on your business, so focus on what you can influence.
Importantly, and highlighted as a Level 2 requirement of the CMMC, assessments must include threats and vulnerabilities in your supply chain from subcontractors, partners, vendors and even customers, since they can all affect your overall ability to manage risks effectively. Risk assessments, either formal or informal, can be conducted at the organisation level, the mission or business process level, or the system level and at any phase in the system development lifecycle.
Threats and vulnerabilities
Threats can come from a wide variety of sources and take on many guises. By tying each threat to the assets they may target and the potential impact you would suffer if the breach was successful, you can determine the level of control you need to apply to mitigate the risks.
Threats don’t always come in the guise of a stereotypical hacker, and any parts of the business where vulnerabilities could permit a threat to cause harm need to be included in your risk modelling. The CMMC lists six kinds of threat you should be evaluating as you move towards managing the risks they cause:
- Weaknesses in business processes;
- Accidental or inadvertent harm to information assets;
- Malicious (intentional) harm to information assets (insider threat and fraud);
- Systems failure – the systems don’t perform as intended (not just technical systems);
- Technology failures; and
- External factors, such as natural disasters and supply chain breaches.
At CMMC Maturity Level 2, you can perform either formal or informal risk assessments. Either method is acceptable. However, proceeding to Maturity Level 3 and beyond, you’ll need to implement a formal risk assessment methodology and qualify your evaluation of the threats based on tacit knowledge of your assets and the motivations (and means) of the attacker. A formal risk assessment methodology ensures you follow a standard approach for threat categorisation, and that the entire process is documented end-to-end. CMMC explains the crucial differences between a risk assessment and a vulnerability assessment, since vulnerability is just one input into your risk calculation.
Maturing your risk management approach
To get to CMMC Maturity Level 3, you need to focus on the overall approach to risk management and ensure the process is complete, including the use of predefined risk categories, sources and the measurement criteria feeding into each assessment. Level 3 also demands you have a programme in place to perform periodic evaluations and can mitigate the threat of recurrence of a risk after an incident.
Risk assessments need to be conducted on more than just your technology systems and should include threats and vulnerabilities affecting your people and your processes, your information and your facilities. By widening your security risk perspective to include these additional business lenses, you gain a complete view of organisational business risk. The outcome of this process, while taking longer to achieve, serves you better in communicating overall security risk (and your current security posture) to the board, so helps in your executive communications strategy from the security team.
Once you have assessed a security risk, if its rating is too high for your comfort, you’ll need to implement a mitigation strategy to manage the risk and bring its score down to an acceptable level. Mitigation strategies typically involve designing and implementing controls (or altering business practices) and updating your service continuity plans. You might also consider how you address risks that cannot be brought into a manageable range, through external strategies such as cyber insurance or putting some of the requirements for mitigating controls back onto your supply chain.
Managed within the risk register, you’ll also record a risk mitigation plan for each risk, specifying how you avoid, accept, monitor, defer, transfer and mitigate them. Mitigation strategies are specified as to how you reduce the likelihood or eradicate the vulnerability, as well as lowering the rating through third-party transference. CMMC lists several examples of the kinds of mitigation strategies you could implement, which are summarised here:
- How you reduce the threat or vulnerability;
- How you limit risk exposure;
- Implemented controls;
- Responsible staff for mitigation plans;
- Implementation details; and
- Metrics for measuring success.
Advanced security risk management
To reach the higher CMMC Maturity Levels, you need to implement threat profiles using analysis of adversary tools, techniques, and procedures (TTPs) to understand exposure better. The use of threat intelligence is vital to achieving this and your security operations capability will be tying risk mitigation strategies to detection and response capabilities in the SOC. This requires an advanced understanding of these TTPs and how the threat might be discovered in the environment.
Technology is key for advanced SOC operators tying adversarial techniques and procedures to operational security processes. Next generation SIEM capabilities with threat intelligence and behavioural analytics help provide risk reporting for business stakeholders.