What is Kubernetes Security Posture Management (KSPM)?

You've heard of Cloud Security Posture Management (CSPM) – or at least, you may have if you follow modern security trends. But what about Kubernetes Security Posture Management (KSPM)?

By adapting security principles to the unique challenges of securing Kubernetes cluster infrastructure and workloads, KSPM plays a central role in protecting K8s environments from risks. Keep reading for a deep dive into the topic as we discuss what KSPM means, how it works, how it relates to CSPM and how to implement an effective KSPM strategy.

What is Kubernetes Security Posture Management (KSPM)?

Kubernetes Security Posture Management (KSPM) is the practice of managing all of the security risks and threats that can affect Kubernetes.

KSPM addresses security challenges related to Kubernetes infrastructure – such as the control plane and worker nodes. It also helps protect workloads hosted on Kubernetes – meaning the applications that run inside Pods and containers.

The term Kubernetes Security Posture Management reflects the concept of treating overall security capabilities as a measurement of an organization's "security posture" – meaning its state of readiness against security threats. Just as having a healthy body posture helps protect you from negative health consequences, a strong security posture minimizes your risk of experiencing a breach. 

KSPM vs. CSPM

In a conceptual sense, Kubernetes Security Posture Management is similar to Cloud Security Posture Management (CSPM), a practice that focuses on managing the security risks specific to cloud infrastructure and workloads to improve overall security posture in any cloud environment.

However, because Kubernetes is different in certain respects from generic cloud platforms, there are important differences between KSPM and CSPM. For example:

• Although managing access control configurations is an important part of both KSPM and CSPM, KSPM focuses on permissions configured using the Kubernetes Role-Based Access Control (RBAC) framework, whereas CSPM manages settings via cloud providers' Identity and Access Management (IAM) frameworks.
• KSPM addresses security challenges that are specific to Kubernetes-based, containerized workloads, such as insecure container images. This isn't a key focus of CSPM, since cloud-based applications are not necessarily containerized.
• Because cloud computing is a broader category than Kubernetes, CSPM is associated with a broader set of practices and tools. In contrast, KSPM focuses rather narrowly on security protections that apply to Kubernetes alone.

We should note that many Kubernetes environments are hosted in public clouds (although Kubernetes on-premises is also, of course, very much a thing). In that sense, there is a lot of overlap between KSPM and CSPM. But you can think of KSPM as a practice that deals with the Kubernetes-based parts of your cloud environment, whereas CSPM is a broader practice that extends to managing security posture for all types of cloud workloads, not just those running inside a Kubernetes cluster.

How does KSPM work?

KSPM is a high-level practice that different organizations can implement in different ways. That said, in most cases an effective KSPM strategy boils down to the following key steps:

1. Identify security goals: First, organizations decide which security policies they want to establish in their Kubernetes clusters. The rules should reflect the overall security posture they aim to enforce. For instance, they may want to ensure that certain workloads are isolated at the namespace level, or restrict which resources a given service account can access.
2. Define security policies: After setting goals, Kubernetes admins can write rules for their KSPM tooling that describe which types of security policies the tools should enforce. These rules provide the context that KSPM solutions need to determine what constitutes a risk. In some cases – like a vulnerable container image – risks are obvious. But in others, the definition of risk depends on what a given resource or workload is supposed to do and which level or risk the organization can tolerate for it.
3. Scan configurations: Using automated Kubernetes security scanners, security teams can review settings inside Kubernetes for misconfigurations that might lead to unintended access.
4. Detect, assess and alert: In addition to scanning security policies, teams can monitor Kubernetes to detect unusual activity, such as anomalous actions recorded by the Kubernetes auditing framework, then generate alerts as needed.
5. Remediate: When Kubernetes security tools reveal risks, security teams respond by mitigating each issue at its source – or, if that's not possible, taking steps to isolate the issue in order to minimize the scope of affected resources.

Key components of KSPM solutions

Because Kubernetes Security Posture Management addresses multiple types of security threats and risks, it includes several different components.

Continuous monitoring

Continuous monitoring is the practice of collecting data from Kubernetes and analyzing it in real time to detect risks.

Kubernetes audit logs, which record access events inside Kubernetes, are one key data source for monitoring. Applications may also produce their own authentication or auditing logs, which KSPM software can scan. Kubernetes network traffic data, too, is a valuable source of monitoring insights.

Configuration scanning and validation

In Kubernetes, virtually all configurations are defined in code. By scanning this code, KSPM solutions can detect issues, such as accounts with unnecessary privileges, that could expose Kubernetes clusters or workloads to attack.

Security alerting and reporting

KSPM solutions can generate alerts so that admins are aware of the risks that exist in their environments. They can also produce reports that track overall security trends. Reports are valuable for understanding how your security strategy and outcomes change over time. They may also be important for auditing purposes because they allow you to demonstrate that you have security practices in place.

Security automation

In addition to generating alerts, Kubernetes Security Posture Management solutions can in some cases automatically remediate issues. This is valuable because it allows organizations to block active threats immediately, without waiting for humans to respond.

In the context of KSPM, security automations can't mitigate every type of threat or risk. But they can fix many routine issues, such as correcting typos in security policies or updating network policies to block malicious traffic.

Benefits of KSPM for cloud security strategy: examples

To illustrate what KSPM looks like in practice, consider the following examples of common Kubernetes vulnerabilities and how KSPM can help mitigate them.

Identifying issues with Role-Based Access Control

Although Kubernetes offers a built-in RBAC framework to manage user identities and permissions, it doesn't automatically detect mistakes or oversights in RBAC rules that could lead to risks. For example, mismatches between Roles and RoleBindings could result in some users receiving permissions that should not be available to them. Or, simple typos might cause Kubernetes to misinterpret an RBAC configuration in a way that leads to excess privileges.

By automatically scanning RBAC configurations, however, KSPM helps to ensure that RBAC policies are configured properly. This is true not just at the time when admins initially set up RBAC rules, but also whenever they make a change.

Detecting deviations from network security policies

Alongside detecting mistakes in RBAC configurations, KSPM can identify oversights in Kubernetes Network Policies – such as configurations that accidentally open up ports that should not be open, or that expose private workloads to the public Internet.

Recommending or automating remediation

KSPM isn't just for detecting risks. It can also assist with remediation by recommending fixes, or even applying them automatically in some cases.

For example, imagine that you've deployed a container based on a container image that is subject to known security vulnerabilities. A Kubernetes Security Posture Management tool might suggest a newer version of the image that includes a patch to fix the security vulnerabilities. Or, the tool could potentially even update your configuration and redeploy the container for you based on the patched image.

Catching human errors and oversights

We've already mentioned some examples of how KSPM can help mitigate issues caused by human errors and oversights, such as typos in RBAC policies. But we'll mention it again because protecting admins from themselves is one of the key purposes of KSPM.

In addition to typos that lead to misinterpretation of security policies in Kubernetes, KSPM provides a means of helping to catch issues such as workloads that don't have any security or access controls in place at all because an admin forgot to set them up. It can also protect against improperly indented YAML code – a simple yet pervasive problem that can be another reason why Kubenetes fails to apply security policies properly.

Validating third-party configurations

One of the nice things about living in today's cloud-native world is that there is a whole plethora of resources available from third parties that you can apply inside a Kubernetes environment. For example, you can find thousands of Kubernetes manifests on GitHub, which you can copy and paste into your Kubernetes cluster to deploy workloads. This saves you from having to configure the resources yourself from scratch.

But the problem with borrowing third-party configurations, of course, is that no one can guarantee they're secure. By allowing you to scan and validate resources you obtain from outside sources, KSPM helps protect against risks introduced via third-party configurations.

Enforcing Kubernetes compliance

KSPM helps enforce Kubernetes compliance, meaning best practices that organizations should follow when configuring and managing Kubernetes clusters.

There are no major compliance policies that focus on Kubernetes specifically. However, many regulations include rules requiring organizations to take reasonable measures to mitigate cybersecurity risks and threats. For instance, PCI DSS (a compliance standard that applies to organizations that process digital payments) generally requires security monitoring. Deploying KSPM tools that validate configurations and scan for threats could be one way to help meet this requirement for organizations that use Kubernetes.

4 best practices for making the most of KSPM

Adopting a KSPM strategy is a step toward improving overall Kubernetes security. How effective your KSPM practices turn out to be, however, depends on how well you adhere to KSPM best practices, such as the following.

1. Adopting KSPM alongside other security tools

Since KSPM is only one element of a broader security strategy, most organizations should use KSPM in conjunction with other types of security tools or solutions.

For instance, a KSPM tool could help to validate network policies inside Kubernetes from a security perspective. At the same time, a cloud security scanner could examine networking rules that you set up using your cloud provider's tooling. Since the latter are external to Kubernetes, KSPM tools wouldn't detect security issues inside them.

2. Scan continuously

Threat actors don't give you a grace period after breaking into your environment before they start doing bad things. For that reason, you should scan your Kubernetes configurations continuously, rather than scanning in batches or on a periodic basis. Continuous scanning maximizes your chances of detecting risks as soon as they arise – which in turn means you can remediate them before the bad guys exploit them.

3. Keep rules up-to-date

Most Kubernetes clusters and workloads change frequently. As a result, a configuration that might be secure at one moment could be insecure the next due to changes in a workload's purpose or the users that should have access to it.

For this reason, it's important to keep the rules that power KSPM tools up to date. These rules allow KSPM solutions to determine what's normal and what's a risk at any given moment, based on your organization's defined risks.

4. Categorize risks

In cases where KSPM tools reveal a high volume of risks, remediating all of them at once may not be feasible. That's why you should categorize risks by identifying which ones are most serious for your organization.

For instance, a vulnerable container image that is deployed inside a dev/test namespace and isolated from the network probably does not pose as serious of a risk as an app running in production based on a vulnerable image.

What to look for in a KSPM solution

There are plenty of tools out there today that market themselves as KSPM solutions. When evaluating your options, consider how each tool compares in the following key categories.

1. Continuous monitoring

Can the KSPM solution monitor your Kubernetes clusters and workloads on an ongoing basis? Or does it only allow you to perform one-off scans?

Consider, too, whether continuous monitoring features are limited to collecting and analyzing certain types of data sources, or whether the tool can continuously monitor any type of data.

2. Compliance assessments

Compliance assessments allow you to determine automatically how well your configurations conform to compliance mandates or standard security best practices. A successful compliance assessment by a KSPM tool doesn't guarantee that your workloads are as secure as they can, but running this type of analysis is a simple and effective way of reviewing the overall effectiveness of your security policies or configurations.

3. Built-in rules

KSPM solutions that offer built-in rules for defining threats make it easier to get started because you don't have to write all rules from scratch. Typically, you'll need to customize and add to the built-in rules because they won't cover every type of risk your organization wants to control. But they're a start.

4. Automated remediation

As we mentioned, some KSPM tools can automatically fix security issues. If automated remediation is important to your organization – as it may be if you have limited security staff – consider KSPM tooling that offers this type of feature.

Kubernetes Security Posture Management with groundcover

We built groundcover primarily to be a Kubernetes monitoring and observability solution, not a KSPM tool. We're not going to tell you that groundcover can handle all of your Kubernetes security needs, because it can't. What groundcover can help you do, however, is analyze Kubernetes metrics related to performance and resource consumption trends, then use that data to contextualize and correlate security issues.

For instance, if you want to know whether a service has stopped responding because your Kubernetes cluster simply ran short on CPU or because someone is DDoSing it, groundcover provides the insight you need to tell the difference. Likewise, groundcover can help identify unusual spikes in resource consumption, which could be a sign of malicious activity like cryptojacking.

Put simply, groundcover delivers additional context for analyzing and troubleshooting Kubernetes security issues – and when it comes to security especially, context is everything.

KSPM: Not just another acronym

If you came into this article wondering what KSPM meant or why you should have to learn yet another IT acronym, we hope we've made clear why KSPM is much more than just another buzzword. Kubernetes presents some unique security challenges, and KSPM is key for helping to address them. Think of it as a Kubernetes health check, but one that addresses security instead of performance.