Nowadays, most of the applications are deployed on containers and orchestrated using Kubernetes or similar technology. Due to this, the performance, stability, and scalability are highly increased. But, it also widens up the attack surface if proper security controls, techniques, tools, and practices are not followed/used.
So, if your application is running on containers or if you are thinking about deploying containers, then learning about container security best practices is a must. And, here you will find all the details required to secure containers.
Container Security: What Is It and Why You Need It?
Container security refers to the constant effort of protecting the containers, application, and all other associated underlying components. It covers the entire infrastructure, including the hypervisors, operating systems, hots machines, orchestrations, and kernels, supporting seamless software execution.
There are numerous reasons why container security is important, and some of them are listed below:
- It helps to reduce the attack surface and ensure attackers are prevented.
- It supports maintaining the container’s health and performance.
- It aids in retaining the data integrity, availability, and confidentiality.
- It helps in safeguarding mission-critical components.
- It eases vulnerability management, minimizing risk factors and attack threats.
Challenges and Risks Associated With Container Security
The following are the primary risks associated with container security. You must consider them while choosing the most reliable best practices for your container infrastructure.
1: The Distributed Container Architecture
An application deployed on the container is distributed among different servers and operating systems. Numerous processes run in the background to maintain communication, stability, performance, and scalability. Due to this, it becomes difficult to find security mechanisms, tools, and best practices that can be implemented for all components.
2: Container Ephemerality
There are many use cases where short-lived containers are used. The main purpose of such containers is to execute their process and get deleted automatically. Sometimes, the malware or attacker can be hidden in an ephemeral container. And they can take advantage of its auto-deletion.
For instance, the malware executed its function of spreading the virus in other containers and then got deleted with the short-lived container. So, the loss of attack evidence is quite a challenge.
3: Third-party and Open-Source Risks
Containers and applications running on containers use several third-party and open-source components and APIs to process data. Due to this, an additional risk of getting hacked occurs. If the open-source component is not developed, updated, or patched correctly, it can become a root cause for a cyber-attack, risking the cost and business reputation.
4: Securing the Network With 100% Availability
Networks are highly prone to receive cyber-attacks. Even most hackers try to exploit the open ports in network devices to access the resources, modify them, and then exploit the containers. Therefore, when you think of container security, you must also focus on network security. Otherwise, the possibility of getting breached will remain the same.
Container Security Best Practices For Extended Run
The top tactics, techniques, and approaches for DevOps experts to maintain and improve container security are followed.
1: Utilize Secure Images
When a container is created, images are used by DevOps experts. Such images are the fundamentals of containers, which must be secured using robust mechanisms. If an attacker exploits an image, your whole container is compromised.
You should use an image containing the complete application and all associated dependencies to secure your containers. In addition, all significant libraries and tools should also be present in the image, making it a single compiled binary.
However, you need to ensure that additional, duplicate, and unnecessary components are removed before deployment. It will reduce the attack surface, helping to prevent attackers, loopholes, and exploitations.
2: Configure Strict Registry Security
To prevent tampering over the repository registries, you should configure the security controls, enabling you to retain the integrity and prevent unauthorized access.
Firstly, you should focus on retaining the image integrity. For this, you can use the Cosign tool, which is a component of the Sigstore. In addition, if you use Docker for your container purposes, you can utilize the Notary open-source tool.
Furthermore, you will be required to configure an access list to allow only authorized users to access the container images. You can implement such lists based on the MAC address, user account, IP address, department, and more. By analyzing the requirements of your organization, it will be easy to decide who will be allowed.
3: Safeguard Deployment Procedure
Let your containers follow the concept of immutability. It means that when a container runs, you can not access and modify it in between. Also, you need to create new images and delete the old ones to let a new functionality take place. Due to this, if a malicious function is running, you will be able to effortlessly detect it.
Furthermore, to safeguard the image, scan and sign it to prevent modification. To ensure a secure environment, configure a VPC (Virtual Private Cloud), harden the operating system, configure the access list, and restrict API and third-party component access. You can even configure a firewall and define policies for custom security.
4: Strengthen Container Infrastructure Security
If your container infrastructure is secure, then your container security will be more hardened. To safeguard the infrastructure, you shall follow the below approaches:
- The containers must be configured in a segmented network according to their use case and requirements.
- You should use only transport layer security (TLS) to communicate with the containers.
- Additional controls must be configured for containers processing confidential and sensitive details.
- You should scan the network for open ports and close them promptly to prevent cyber-attacks.
- Complete infrastructure should be monitored thoroughly, and frequent vulnerability assessments must be performed.
- You need to ensure that only scanned, signed, and tested images are run on the containers in a production environment.
5: Reliably Manage all the Secrets
Secrets refer to the account credentials and private/public key pairs used to authenticate and run the containers. To secure your credentials, you can use a number of approaches, such as implementing orchestration, using a Vault, or using a secret management service offered by cloud providers.
Additionally, you should rotate the keys occasionally, as it will reduce the probability of unauthorized access through breached/leaked credentials. Mainly, DevOps professionals consider using a key only for a week or month, depending on the criticality of the container.
Furthermore, you should perform encryption, hashing, and salting on all passwords. It will prevent illegitimate actors from reading the content. Therefore, with all these approaches, your containers will be secured.
6: Provide Training to the Team
Providing training to the DevOps team is an integral best practice that every organization should follow. It will help them prevent phishing, vishing, whaling, and similar social engineering attacks. In addition, every professional in the team will be able to detect significant irregularities that compromise the overall security.
In the training, you should focus on the following factors:
- Hire a container security expert to provide the training.
- Conduct mock security drills to analyze the level of understanding among the employees.
- Provide online training modules for constant learning.
- Support the professionals in learning about working with each other to gain more clarity about their working environment and required security metrics.
7: Prefer using Short-Lived Containers
Configuring short-lived containers must be your priority and one of the technical goals. It means that only the required file should be added to the container so that it can work efficiently and provide the necessary output. By following this practice, you will reduce the attack surface, eventually lowering the cyber-attack probability.
Furthermore, if any of your executable files or codebases are quite large in size, then you should go through them and remove the unnecessary, duplicate, and commented code. As a result, the container size, attack surface, and resource utilization will be reduced. Thus, you will also save on the cost required for advanced security and resource configuration and management.
8: Focus on Avoiding Common Mistakes
Most of the container security teams focus on the top layer of security, but they forget basic security hygiene. Focusing on the significant and common approaches listed below will also help you protect your containers.
- You should use only the legit operating systems and software to build codebases.
- You must sign the code and container image to retain their authenticity.
- Protect the admin accounts with multi-factor authentication.
- Configure a firewall, log server, and access-control list in the network.
- Isolate the public and private network.
- Follow the NIST, ISO, and other regulatory guidelines.
9: Frequently Monitor, Scan and Patch
Monitoring, scanning, and patching are considered the three primary pillars of container security maintenance. By using them, you can ensure that your containers are protected in real-time. You should use a monitoring tool and log server to analyze the current health, resource utilization, and container communication with other components.
Due to this, you will be able to detect any unexpected and malicious activity being executed in the background. Mainly, it’s helpful to discover malware and backdoors. In addition, you should schedule the container vulnerability scanning to find loopholes. Also, patch the vulnerabilities promptly to avoid attacks and data leaks.
Tools To Consider For Robust Container Security
Security experts use numerous tools to maintain container security. You can choose the tools per your requirements. But, having a tool from all the following categories is highly recommended.
#1: Container Monitoring Tools
You must have monitoring in place to gain higher observability of your container infrastructure. It will help you analyze the current performance, health, security status, and resource utilization. In addition, you can keep track of container applications with such a tool.
Some of the top monitoring tools are as follows:
- Prometheus & Grafana
- Sumo Logic
Once you start using any of the monitoring tools, bottlenecks will be identified and resolved easily, performance metrics will be maintained, instant security actions will be taken, and accurate resources will be used, helping you minimize risks.
#2: Container Scanning Tools
The primary purpose of container scanning tools is to find vulnerable loopholes in their architecture. Scanning is a part of the vulnerability assessment procedure, which helps to discover potential threats and risks associated with container security.
For scanning purposes, you should consider using the tools below:
- Aqua Security
- Docker Bench
- Anchore Engine
With the aid of these tools, you can patch your container images and make them trusted for your infrastructure. Thus, the scanning tool will help you complete the best practice goal of using trusted and secure images.
#3: Container Testing Tools
Container testing mainly refers to testing the application using SCA (Software Composition Analysis), DAST (Dynamic Application Security Testing), and SAST (Static Application Security Testing) approaches.
Before deploying your app to the container, you must test it to find vulnerabilities, patch them, and update the codebase accordingly. It helps to reduce the attack surface, increase the probability of meeting performance metrics in real-time, and prevent threats.
You can use the below top container testing tools:
#4: Network Scanning and Security Tools
A network is created between containers and servers through which they share data. If an attacker exploits an open port or gains unauthorized access over the network, container data can be breached. So, to secure the containers, it’s essential to scan the network, find loopholes and open ports, and patch them promptly.
You can use the following network scanning tools:
In addition, to strengthen network security, you can configure a firewall, create a DMZ, and segment networks using VLANs and SDNs. As a result, intruders will not be allowed to access the containers, and every component will function impeccably in a secure environment.
To safeguard the containers, you should follow the mentioned best practices of using secure images, managing secrets in a vault, training the team, and avoiding misconfigurations.
In addition, you must use the appropriate tools for monitoring, network security, app testing, and container scanning purposes. Once you adopt all such mechanisms, the container security will be strengthened, preventing cyber-attacks and maintaining data security.