What is Kubernetes Runtime Security?
Kubernetes runtime security can be defined as the tools and technologies that are utilized to protect container workloads on Kubernetes at runtime. It enables the security team to monitor containers in real-time and protect the workloads from an array of threats that can jeopardize the live environment.
It can also be considered a part of container security and workload as it helps address security issues, from container instantiation to termination. This mechanism combines a range of techniques that also help monitor network activity and file access, ultimately helping protect against possible threats.
When a container has been deployed, different threats might arise, which include malware hiding in container images, privilege escalation attacks, malicious container deployment, and unauthorized access to containers to secrets. In today’s world, attackers are getting advanced with their attacks, and they are finding ways to inject malware container images.
Even though security is implemented, development pipeline and access control are deployed for container isolation, still there is no guarantee a container won’t be compromised in runtime. So, having a Kubernetes runtime security will provide the final protection and enable the security team to monitor and address threats that may arise during runtime.
Kubernetes Runtime Security Challenges and Risks
In modern times, Kubernetes has become a staple for most organizations, and Kubernetes runtime security serves as an effective security solution for protecting workloads. Despite offering comprehensive security, there are certain Kubernetes runtime challenges and risks that are faced by many organizations. They are:
Privilege Escalation
When cybercriminals get into the Kubernetes environment, they can easily escalate their access privilege to carry out their malicious activity. Privilege escalation is quite a common Kubernetes runtime security threat that has been faced by numerous enterprises that have adopted containerized applications.
Misconfigurations
Another textbook challenge related to Kubernetes runtime security is misconfigurations and insecure configurations that has impacted numerous organization. Clusters that are deployed often come with some sort of misconfiguration.
A recent survey stated that around 900,000 Kubernetes instances were found exposed online where some of them are vulnerable to data-exposing attacks.
Default Kubernetes Settings
Many DevOps often utilize default settings to deploy clusters but this trend also leads to threats like unauthorized access by threat actors. Any attackers can utilize the default settings to get entry into the environment. The only way to solve it is by customizing the settings, creating firewalls, and implementing encryption.
Malware
Malwares like cryptominers and DNS hijackers has been a serious security threat and most of the time they are found in container images. It is a common security threat that occurs even after thorough container image scanning. In 2022, a survey stated that around 1600 containers in Docker Hub were infected by malware. When such containers get deployed, it creates serious security threats to the live environment.
Vulnerabilities in Kubernetes and Containers
Containers and Kubernetes are often vulnerable to known CVEs, which causes them to be exploited by malicious actors. Even though Kubernetes are protected by various security measures, some known exploits still stay intact.
Kubernetes API Vulnerabilities
Kubernetes API are quite vulnerable and they pose significant risk to the containerized application after they are deployed. When API endpoints are properly secured, it allows attackers to launch cyberattacks like DoS and disrupt the running application, leading to disruption in business operation.
RBAC Policies
RBAC policies serve as a native methodology for managing authorization to Kubernetes resources. When RBAC policies are poorly managed and controlled, it leads to serious data breaches where attackers get their hands on sensitive information. Moreover, improper permission management also leads to unauthorized data manipulation and other issues, jeopardizing the integrity of the system.
Insufficient Network Segmentation
Network traffic segmentation between pods and namespace is an important aspect for Kubernetes clusters and it is mainly due to the flat network model. However, when insufficient network segmentation takes place, it enables attackers to perform lateral movement and jeopardize the containerized application.
Insider Threat
Another huge Kubernetes runtime security threat faced by many organizations is insider threats. Threat actors can utilize the cluster access to gain entry and launch DoS or any other attack.
Native Kubernetes Runtime Security Tools
Even though Kubernetes itself serves as a runtime security tool, it only offers auditing and allows the organization to record logs that are useful for tracking resource requests to Kubernetes API. That is why it leverages a compact set of native tools to enable an organization to minimize runtime risks. These tools are:
Admission Controller
Kubernetes runtime security tool comes equipped with an admission controller whose main task is to minimize the number of modifications that can be made to Kubernetes API endpoints.
Secrets
K8s also come with Secrets that are basically data objects allowing organizations to store various sensitive information like passwords, API keys, and other credentials. It comes highly useful in safeguarding the Kubernetes runtime as it keeps the sensitive information out of Pod and container images.
Audit Logs
For Kubernetes runtime security, it is vital to have audit logs because it provides the security team with logs of all the activities happening in a cluster. Security team can utilize the logs to analyze and detect malicious behavior in API activity.
Network Policies
Kubernetes runtime security also utilizes network policies that enable the team to implement respective policies at the network and transport layers. These network policies are similar to firewall rules, allowing the team to easily handle the policies.
RBAC
Role based access controls serve as an important native tool for administrators of your organization because using this tool they minimize the Kubernetes API access based on the entity’s privilege.
Organizations often utilize some external Kubernetes runtime security tools to effectively eliminate threats. These tools are:
Seccomp
For Kubernetes runtime security, some organization often utilize Seccomp which is a Linux based kernel tool that helps your team to enforce processes run in a secured state. When a process is enforced, Seccomp bars all the system calls except the exit, reading & writing to opened files and sigreturn.
SELinux
SELinux serves as a kernel module that enables the security team to define a lot of access control. It helps the team in defining rules at a granular level regarding which resources a container can access and the type of activity it can perform.
AppArmor
Another external tool that is widely used for Kubernetes runtime security is AppArmor that helps in defining a large number of access control rules. It has similar functionality with that of Seccomp and offers the same general result.
Kubernetes Runtime Security Best Practices
When addressing Kubernetes runtime security threats, utilizing the native tools won’t be sufficient, as you will have to take a comprehensive approach. You will have to employ certain best practices that will help in minimizing most of the threats. Here are those best practices:
Avoid Running Containers as Root
When you run a container as root, it enables cybercriminals to launch privilege escalation attacks and get access to all the sensitive customer information. However, if you ensure all the containers run normally, it will mitigate all the chances of threats.
Auditing and Automating Container Configurations
It is important that you should audit all the configurations and automate the process of configuration deployment through IaC because it will limit the chances of exploitation through misconfiguration.
Some examples of misconfigurations are keeping sensitive information apart from Secrets and creating database instances in the Kubernet that are internet-facing.
Locking Down The Network Layer
You should utilize RBAC, Kubernetes network policies, and tools like NGFW and IP/IDS because they can help identify and prevent threats that can affect the workloads. Besides enforcing the policies, you should also prevent the chance of exposing Docker daemon sockets publicly because attackers can easily exploit them.
Prevent Privileged Mode
Privilege flag is one of the biggest issues with Kubernetes runtime security. When running any container, it should be done without having a privileged flag because it enables the container to avoid going through various security checks.
Utilizing Read-Only Filesystems
Another best practice you can follow for optimum K8s runtime security is only utilizing read-only filesystems because it eliminates the chance of attackers injecting malware code into the container’s filesystem. The read-only filesystems also prevent attackers from exploiting any vulnerabilities or making any modification.
Running Trusted Container Images
You should only run trusted container images because it will eliminate the chance of running risky images from public repositories. When your administrator runs a compromised image from a public repository, it not only makes the Kubernetes runtime environment vulnerable but also gives attackers a chance to attack the workloads.
Securing the Kernel Level
Beside utilizing the native K8s runtime security tools, you should also leverage external solutions like AppArmor, cgroups, Seccomp, and SELinux. These tools can provide an additional security layer to Kubernetes runtime security at kernel level.
Tools like AppArmor help in defining access control roles and policies to restrict access to kernel resources, minimizing any chance of unnecessary privilege.
Thorough Scanning of External Policy Files
To ensure optimum runtime security, you should always perform a thorough scanning of files or profiles created through external tools like SELinux or AppArmor. Overlooking the files can jeopardize the whole runtime security as they often carry vulnerabilities or misconfigurations.
Focusing Dev/Test
One of the best ways to maintain robust K8s runtime security is by securing dev/test. Identifying and remediating runtime security threats in the dev/test can minimize the chance of exploitation at runtime and prevent attackers from accessing sensitive data.
Maintain a Robust Incident Response Plan
Even if you maintain an effective Kubernetes runtime security, there are occasions when an attacker will bypass them. You should stay ready to address such an attack with a robust incident response plan. The incident response plan will serve as a guidebook that will help you navigate through different runtime security threats and remediate them.
Kubernetes Runtime Security with CloudDefense.AI
CloudDefense.AI, with its Kubernetes Security Posture Management, serves as an ideal solution for enterprises who are looking to secure their Kubernetes runtime security. It serves as an all-in-one solution for your Kubernetes environment that gives you a centralized dashboard to address misconfiguration in the runtime. With this solution, you can effortlessly navigate through threats as it offers you benefits like:
- Automated Cluster Scans- Using CloudDefense.AI’s KSPM, you can automate across your K8s clusters and ensure your cluster remains secure without having you to go through any complexity.
- Quick Misconfiguration Detection- This platform can help you quickly detect misconfigurations and provide real-time alerts to enable you to address all the vulnerabilities.
- Cloud Asset Management- With this solution, you get a holistic asset management solution that helps you get visibility into workloads, identities, and resources in K8s.
- Full-Stack Risk Assessment- CloudDefense.AI provides a full stack risk assessment by combining container image scanning, IAM misconfiguration detection and network exposure visualization.
- Thorough Remediation- Using this solution, you can not only quickly address policy breaches, misconfigurations, and risky privileges but also remediate them through automated mitigation.
- Real-time threat analysis- This solution is known for its real-time threat analysis where it continuously monitors the Kubernetes environment in runtime and provides immediate response to threats.
- Custom Security Policies- CloudDefense.AI also allows you to define custom policies and enforce rules for optimum protection of your Kubernetes environment.
- Compliance Enforcement- Adhering to regulatory requirements while maintaining Kubernetes runtime security is vital for every organization. This solution helps in maintaining regulatory compliance by making sure clusters follow the CIS and hardening guide.
If you want to learn more about KSPM from CloudDefense.AI, you should sign up for the free live demo.
