Kubernetes is an open-source system for automating deployment, scaling and management of containerized applications. But these new deployments can cause attacks and exploits from attackers and insiders as traditional environments which makes kubernetes security a prime concern for all deployments.
Nearly, 94% of organizations have encountered a genuine security issue within a year in their container environment, 69% having detected misconfigurations, 27% experienced runtime security issues and also 24% found significant vulnerabilities to remediate. Each of these issues relates to a container lifecycle phase. You can differentiate these vulnerabilities during build/deploy phase, runtime phase etc.
Kubernetes Vulnerabilities And Attack Vectors-
Attacks on Kubernetes containers running in pods can come internally by insiders or externally through the network, that includes victims of phishing attacks whose system becomes a mediator for insider attacks. Some of the examples are as follows-
1. Unauthorized connections between pods- Compromised containers can try to connect with running pods to attack. Layer 3 network controls whitelisting pod IP addresses can offer protection but attacks over trusted IP addresses can only be detected with Layer 7 network filtering.
2. Container compromise- Application misconfiguration or vulnerability empowers the attacker to get into a container to start probing for weaknesses in the network, process controls or file system.
3. Data exfiltration from a pod- Data stealing is generally carried out by combination of techniques, which can include a reverse shell in a pod connecting to a command/control server and network tunneling to hide confidential information.
Kubernetes Security Best Practices: Infrastructure Security-
1. Update your Kubernetes-
Only the last three versions of Kubernetes are supported, including security patches for new vulnerabilities. Hence if severe vulnerability is discovered, and you are four versions behind, then your version will not receive a patch.
2. Securely configure the Kubernetes API server-
Ensure that you’re disabling unauthenticated/anonymous access and using TLS encryption for connections between the kubelets and the API server.
Kubernetes Security Best Practices: Build Phase-
Securing containers and Kubernetes begins in the build phase with securing your container images. Any missed security best practices will be essentially more costly to fix down the line – consequently the expression “shift left” which means implementing security at prior stages as images are built. Scan and secure images are the main things to secure from any known vulnerabilities.
1. Use an image scanner-
Image scanner can identify vulnerabilities in your images, including by layer and tell you whether they are fixable or not. It must scan for vulnerabilities in OS packages and also third-party runtime libraries for the languages being utilized in your containerized applications.
2. Label non-fixable vulnerabilities-
Some of the time there isn’t a fix for a known vulnerability, or the vulnerability is non-critical and hence doesn’t warrant a quick fix. At such time, include them to allow list or filter the scanner output so that you don’t intrude on the development team’s workflows over non-actionable alerts.
3. Don’t include unnecessary components-
Ensure that you’ve removed debugging tools from containers in production. Tools such as Curl should not be included in images.
4. Implement defense-in-depth-
When a security issue is discovered in a container image or a running deployment that utilizes that image, ensure you have policy checks and a remediation workflow set up to recognize and update those images.
Kubernetes Security Best Practices: Deploy Phase-
From a security point of view, you first need visibility into what you’re deploying – and how. At that point you can recognize and respond to security policy violations.
What is being deployed- including data about the image being used, like components or vulnerabilities and pods.
Where it is going to be deployed- namespaces, clusters and nodes.
How it is deployed- regardless of whether it runs privileged, what other deployments it can coordinate with, the pod security context that is applied, if any
What it can access- includes volumes, secrets and also other components like host or orchestrator API
1. Isolate sensitive workloads by using namespaces-
Namespaces are a main isolation boundary for Kubernetes resources. It provides a reference for network policies, access control restrictions and also other important security controls. Separating workloads into namespaces can limit the impact of mistakes or destructive actions by authorize users.
2. Use Kubernetes network policies-
Kubernetes allows every pod to contact other pods. Network segmentation policies are the key security control that can prevent parallel movement across containers for the situation that an attacker breaks in.
Kubernetes Security Best Practices: Runtime Phase-
If you secure containers and Kubernetes deployments at the build and deploy phases also, it can reduce the security incidents at runtime and the efforts required to respond. You should analyse the security related containers activities like, process activity, Network communications between containerized services and external clients and servers, Network communications among containerized services
1. Extend vulnerability scanning to running deployments-
Examine running deployments for new discovered vulnerabilities in notwithstanding scanning for vulnerabilities that exist in compartment pictures.
2. Monitor network traffic –
Analyze and compare your active network traffic to what is allowed according to your Kubernetes network policies. Containerized applications generally use cluster networking, and observing active networking traffic is a decent method to see how applications interact with one another and distinguish unexpected communication. Comparing active traffic will give you the significant data regarding what is happening but is not allowed. With this data you can fix your allowed network policies so that it removes superfluous connections and minimize the chances of attack.
Securing a cluster is a tougher job. To successfully carry out this task, the operator must understand the behavior of an app. A user must consider the software versions running on the cluster, check different features of each app and prevent unreliable access to the cluster. Managing clusters is a challenging task. To keep up with security, all should be ceaselessly checked, properly separated, keep updated and with better verification roles.
These are some best practices for kubernetes security. There can be few others too. If you’re looking to develop a secured software with Kubernetes, then you are at the right place. We have a dedicated team of skilled developers that will help you to build a secured kubernetes software. Connect with solace and get a free quote for secured software development. We will be happy to help you.