Container Security_ Best Practices and Ultimate Checklist

Containers have managed to garner a lot of popularity in the past few years. Even back in 2019, sources reported that around 30% of corporations on a global scale were using containerized applications (apps that run in their own isolated runtime environments), and today, the same sources claim that the number has exploded to 75%. And while containerized applications do offer a wide range of significant advantages for the organizations that use them, these systems can be a bit more difficult to efficiently manage from the aspect of security. Cybersecurity experts often state that, in comparison to more traditional computing platforms, container security can be a bit more challenging to maintain fully.

And the numbers seem to prove the concept. According to a 2021 report, a bit over 60% of all asked chief information security officers said that vulnerability and threat management had been negatively impacted because of the way container runtime environments behave. Why are excerpts reporting these issues? Are there any best practices that will enable security experts to mitigate these negative impacts? In the following article, we will explore the steps you can take to ensure your container security performs at its best.

 Assessing Container Security

Simply put, container security is the process of implementing the necessary security tools, policies, and protocols to help keep these container-based workloads safe from cyber threats.

As such, container security has two main goals:

  •  To secure the runtime configuration:to keep the system functioning effectively, these containers should be able to seamlessly communicate with each other and with the given network services but still remain isolated both from the host system and each other. Some containers usually run with privileged flags. Others will often contain data about host processes. These two categories can often become points of compromise in a corporate system. To avoid this, experts should thoroughly manage Linux namespaces, access controls, and groups.
  • To protect the container image:application developers will usually use the help of open-source tools when they are building containerized systems. And while this makes the development cycle faster and often more cost-effective, it also increases the risks of running into security vulnerabilities. As such, the second main goal of container security protocols is to address these vulnerabilities.

What’s The Catch with Container Security?

When assessing the two goals above, keeping the runtime configuration intact is a more straightforward objective to manage. For starters, there are several great security tools that will help with that, and the latest benchmarks from the CIS (Center for Internet Security) always tend to be perspective and clear. The second goal, or keeping the container images secure, is much more challenging – especially when security experts are dealing with open-source components. In these cases, professionals will usually use four common tool types to keep the software adequately protected:

  • Source-code tests used in the development
  • Image scanners after development
  • Network scanners to get an “outside” perspective of the system
  • Runtime detectors for an “inside” perspective

 Container Testing Checklist

 Source code tests

As mentioned before, these solutions can scan the source code of the container before it’s built. They are also called SCA and SAST (Software Composition Analysis and Static Application Security Test) tools. The first type is able to detect only the vulnerabilities in open-source code, while the latter will also be able to spot vulnerabilities in custom solutions.

The biggest drawback of these scanning tools is that even the latest, automated pieces of software can be cumbersome and slow. As a matter of fact, there’s research out there that shows some development teams bypass these tests to speed up the product delivery time. Furthermore, some of these solutions may detect false positives, which, again, may waste time during the development cycle, and later on, they may also cause headaches for security practitioners.

Still, these solutions are imperative in ensuring proper container security. For instance, SCA tools will be helpful when it comes to licensing restrictions, which are often problematic in the case of open-source code, while SAST tools will come in handy to learn more about custom code-related security deficiencies.

 Image scanners

When developers are ready to build container images, they will usually get stored in registries until they need to be used. Image scanners work by “scanning” the packages within the image and by running build dependency tests to look for new possible dependencies. This type of analysis is also great for identifying already documented vulnerabilities within the container packages. For the most part, these image scanning tests are automated, not slowing down the development cycle, but are still prone to identify false positives.

 Network scanners

Security teams who operate within enterprise-level companies are quite familiar with the way traditional network-based scanners work because this type of scanning tech is actually older than containers themselves.

These are the security solutions that look at the system from an “outside” perspective or the attackers’ perspective. These solutions aim to tell everything security teams there is to know about possible vulnerabilities that plague the application framework, the host operating systems, and even the network devices like routers and switches. These scanners will tell if encryption is being used or whether there are any exposed ports within the system. Still, they won’t be able to tell sufficient information regarding the container’s source-code vulnerabilities because containers aren’t transparent for these traditional vulnerability detectors. 

Runtime vulnerability scanners

Compared to the other tools, these are newer solutions that examine the protocols inside a container that’s running. The detector’s agent observes every process or call to specific functions or calls performed by open-source libraries. Thanks to the way it works, the agent can easily avoid detecting false positives that are triggered by vulnerable libraries that aren’t used in the application or in a way that may enable the attackers to infiltrate the system.

Apart from this, runtime detectors can also tell whether multiplication functions are being used. Features such as these can help both security experts and developers a great deal when it comes to saving time and improving efficiency.

Container Security Best Practices

What organizations and security staff need to understand is that container security isn’t a one-way street or a simple solution. It should be looked at more as a process that should start when the container is being built and expands to evaluating everything that’s in it along with its configuration and incorporates risk analysis that assesses the container’s runtime behavior.

To make this process easier to follow, here’s a best practice checklist for improving container security:

  •   Developers should keep things straightforward:In order to decrease the chances of an attack, developers should strive to remove unnecessary components that aren’t vital to system functions.
  •   Opt for trusted base images: Make sure that the images that the developers use have been scanned and deemed safe for use.
  •   Securing the host operating system:Using scripts for proper host configuration that adheres to the latest CIS benchmarks. Some experts advise using lightweight Linux distributions that are specifically designed with hosting containers in mind.
  •   Manage secrets the right way:Database credentials, SSL keys, API keys, and encryption keys should all be kept from being discovered and compromised. Some experts recommend using a reliable secret management system to improve overall container security.
  •   Consider removing privileges: When you are running privileged containers, you are potentially opening a vulnerability to be exploited by a malicious user who can take over the host system, endangering the complete infrastructure.
  •   Running several source code tests:Although some of the SAST and SCA tools can be cumbersome, they are still a crucial part of good container security practices. Depending on whether you’re using open-source or custom code, you can either use one or the other security solution to analyze and keep track of vulnerabilities and possible license restrictions.
  •   Analyze the app during runtime:Eliminating the problem of false positives that might stem from the scanning methods we talked about above, you also need to scan for runtime vulnerabilities. For the most part, these solutions will be able to help you with security but will also give you more insight into application reliability and performance.

Using Every Tool to Gain The Upper Hand

Experts will often recommend using every scanning method to keep everything safe and running smoothly. Most professionals will also recommend that you combine a runtime detection system with an observation platform so security staff can also better understand the business risks that vulnerabilities represent. For instance, such solutions can analyze everything that’s happening during runtime while also scanning potentially vulnerable libraries in a manner that might open an opportunity for a cyber attack.

Using such a system could be a great addition to filter out the problem of false positives that often causes headaches with the SCA, SAST, and CWPP solutions. Going with a cutting-edge runtime detector means that you will be able to run a scanner that knows whether the internet has access to sensitive information that can be exploited. The AI engines that power these solutions can be able to combine the data with threat context information and generates different reports that reflect the risks associated with each application vulnerability.

Knowing the associated business risk of the possible vulnerabilities can also come in handy when it comes to prioritizing threat management. Remediation actions also need to be handled with care, as finding the necessary solution for a potential threat may not be instantaneous. When experts have identified all priorities and taken the false positives out of the picture, the process of container security becomes a lot like a workflow where problems need to be executed.

In order to make this process even more straightforward, look for solutions that:

  • Automatically identifies problems and recommends possible solutions, workarounds, and upgrades to speed up threat management.
  • Identifies when the vulnerability has been dealt with and upgrades the priority list to show these changes.

 Container Security: A Comprehensive Approach

As you can see from this detailed article, container security is the most effective when security experts implement a multi-layered approach. At the moment, security protocols and solutions simply can’t monitor every single aspect of containerized applications. As such, every scanning technology and detector software can help security teams be more productive with vulnerability identification and threat mitigation.

Knowing how to approach these systems is the key when assessing security effectiveness. From the development cycle to running regular runtime tests, containerized systems rely on continuous observation to be kept secure.