Posted on January 28, 2021
Risk-based Vulnerability Management for SME’s and Startups
I recently was asked a related question and it set me off thinking about how smaller companies could approach such a thing. So, in order to not waste the thought cycles, why not gather them into this blog post?
For SME’s or for organisations not large enough to have a dedicated security team, vulnerability management often involves an annual or quarterly internal/external vulnerability assessment. This generally involves a 2- or 3-day engagement that aims to capture a current snapshot of your network assets and associated vulnerabilities through the scope of an automated vulnerability scanning tool. Often the enterprise security scanning software used to deliver these services, strictly adhere to CVSS or some OWASP based risk taxonomy rating when grading your risks.
In my view this task can be performed by anybody with the ability to enter an IP Network range into a form and press the start button. Ideally you should get someone who knows what they are doing to set this up for you or to help interpret the results. There is only so much value an automated in-house process such as this can provide. Using Nessus or Qualys to do regular and continuous scanning provides useful insights and vulnerability information but it is by no means an all-encompassing solution. I’m happy to assist clients with setting this up in a way they can self-manage and leverage such a tool moving forward and provide documentation on how to best use these tools.
The meat of this post however is what you should be doing afterwards. You have your vulnerability scan results and everything is red or orange or green, now what do you do? You can’t fix everything; do you focus on the issues highlighted as critical? Do you try to deploy patches for everything? Do you panic? The answer of course, is that you hire a friendly penetration tester or knowledgeable security consultant with a deep insight into how these vulnerabilities are leveraged in the real world, to help you break down your assets and remediation plan into actionable chunks. You need to also do further testing to be aware of the critical issues these automated tools will not detect. There will be many.
Practical expertise in reproducing or finding vulnerabilities and determining the REAL-WORLD risk and impact of identified security issues is invaluable. Often attackers will go much further with identified vulnerabilities than can be merely determined by matching issues to a CVSS rating. You need to give penetration testers the right amount of time to correctly evaluate your exposure and risks. They need to have a full view of where the networks or applications they are testing fit within your overall business. What controls are in place to protect them and where potential issues can arise. It allows a much greater understanding to be formed on where your security risks are and allows more context-aware recommendations to be provided to protect your assets.
Making secure design decisions early will save you an incredible amount of grief or effort when your applications become more robust and you are trying to bootstrap in patches or trying to counter active threats. A “3- day Blackbox security review” in your early days probably won’t offset business security risks and you are setting yourself up to fail in future. Get security expertise involved early, train some staff in secure development or coding or outsource secure code reviews. You need to take this seriously as the modern internet punishes those who are complacent.
The best way to leverage a consultant’s time is to give them the documents or information they need to best understand your operation. Don’t stick Firewalls or services in their way to stop them properly testing your applications. Give them source code. Product insights can help them identify the areas you need to focus on and how you should proceed about increasing your overall security. The correct management of uncertainties combined with gaining a better understanding of the likely paths of exploitation, can greatly direct your efforts.
Risk-based vulnerability management differs from the results of a security scanning tool in that you can utilise intelligence-driven remediation and decisions. Leveraging threat intelligence services or greater expertise in the threat landscape or security field to guide where to best spend your time.
With a risk-based approach you ultimately should be focused on securing the areas that are most likely to be attacked by a real-world criminal. Knowledge of real-world attacks and an understanding of the real motivations (financial or information gathering in nature) can better guide your remediation efforts. There are a lot of different concerns that should factor into making a real-world risk calculation and the guidance of security expertise can ensure you prioritise issues that present the most immediate critical risks.
As information security is a rapidly changing and modern field. We don’t have a full view of all of the threats at any one time or have a large statistical and comprehensive historical data-set to model the risks reliably. We are nowhere near having a full enough picture to accurately calculate risk to the same extent that can be achieved in other fields by actuarial scientists. The people closest to decision making and implementing change in an organisation (ie. IT staff and business managers) need to factor in a correct evaluation of risk. Security expertise and threat intelligence can enhance these actions and solutions in a way that drives down risk in a holistic way.
The following are some areas where security risk considerations can enhance your vulnerability management and remediation prioritisation:
- The individual risk rating of each asset and associated threat models.
- Where each asset sits in an overall business context and the criticality of the business function it serves.
- The most up-to-date and continuous visibility of your current assets and their current vulnerabilities.
- Visibility of developing and active threats and the threat groups that target your particular industry.
- Visibility of what vulnerabilities are new and actively being exploited by malware or automatically propagated.
- The complexities involved in deploying patches for each asset or network.
- Where each of your assets or applications fall on a risk scale when compared to other applications or services? Apps widely used are more likely to be valuable to more attackers and targeted.
- Managing uncertainty, unknowns (0days) and the predictive prioritization of mitigation.
All pros and cons must be considered in each situation and for each asset or vulnerability. For advanced threat actors or attack campaigns, having threat intelligence and insight into tactics, techniques and procedures can lead to better security hardening. By understanding the paths threats usually take once a compromise occurs, it can encourage more thoughtful and effective security controls. You can prioritise and monitor for the right things or have the right network security or firewall granularity in place to introduce extra road blocks. It’s an advantage to know what attackers often do.
Introduce more barriers that attackers need to work around or increase your visibility in known to be risky areas. By being smarter about risk you can often increase the time it takes for attackers to carry out their malicious activity or increase the likelihood of you detecting them before they do. They are more likely to make mistakes or set off alarms. This gives vital extra time for would be threat hunters, Incident responders and network security folks to identify and neutralise the threat before it impacts revenue.
A risk-based approach to vulnerability management is essential in modern times and a threat aware approach or security conscious business can be crucial to building your success. Learn from the mistakes others have made. Doing nothing will make you a very likely target and victim. Trying to do too much and patch everything at the same time, will waste vital resources that could be better utilised by focusing on the security issues and risks that are more likely to be exploited. Balance and planning are essential. This is why modern and successful companies have started shifting to asset management, continuous security testing and bug bounty services. You need awareness of the most likely to-be-exploited risks at any time and to develop strategies that will maximize your efforts in an always changing environment. Secure foundations support taller buildings.