Pretty much every organization is moving or has moved to the cloud. That translates to the use of so-called containers that experts say require the utmost protection to ensure business continuity. But what is container security?

What Is Container Security?

Container security has much to do with computer development in the cloud. Simply put, it means protecting all of the assets in a container using various security tools and policies to ensure uninterrupted operations. But what is a container?

A container is a standard software unit that houses code and related programs that allow an application to run quickly and reliably, regardless of the computing environment. Think of it as a shipping container that houses your fully operational mobile office. Everything you need to run your business is there, ready for use, no matter where you set it up.

What Container Components Need Security?

Like a cloud-based container, your mobile office needs protection against all kinds of threats. In a cloud container’s case, that means ensuring the security of the following elements:

  • Container host: Also known as the “host operating system (OS),” this allows the container client and its components to run. A client refers to a hardware or software piece that accesses a service through a server within a network. Take a look at the diagram below.
What Is Container Security
Source: https://en.wikipedia.org/wiki/Client_(computing)#/media/File:Client-server-model.svg
  • Container network traffic: This refers to the communication packets that flow to and from a container. All network traffic must be filtered to ensure that priorities are followed. What needs to be processed first should be accorded more importance. Security is required to make sure that no malicious traffic that can disrupt operations gets into the container.
  • Application within the container: This is simply the code or program housed in a container required for completing a process.
  • Container management stack: This typically includes a privacy container registry (which allows users to modify their privacy settings) and an orchestrator (which automates container processes) in a container deployment. These elements work hand-in-hand to enforce quality and security standards before and during application redeployment (after modifications are made). Organizations that want to take security to another level can add automated scanners to their container management stack. These scanners watch out for vulnerabilities, malware, and data exposure.
  • Application foundation layers: These are the building blocks of the program in a container. Like all other components, they need the utmost protection against known threats, making container scanning critical.
  • Build pipeline: This comprises a set of tasks that pertain to steps in a user’s build or development process. It uses a task catalog that dictates the steps to follow.

What Are the Most Common Container Security Threats?

Like any infrastructure component, containers are not immune to cyber threats, some of which are:

  • Access control exploitation: This occurs when users overlook basic authentication and authorization security for orchestrators (e.g., Kubernetes and Docker), allowing attackers full access to container deployments. Organizations that suffered from such an attack include Tesla and Shopify.
  • Container privilege escalation: This happens when attackers exploit defects or vulnerabilities in container runtimes or the Linux kernel. An example would be when threat actors exploited a Runc bug in container setups. Runc is a low-level container runtime that does the most work in Kubernetes, Docker, and ContainerD setups. In a recent attack, breached containers allowed attackers to overwrite the host Runc library and gain unhindered access to container hosts.
  • Public image and code repository compromise: In 2019, Docker announced that a hacker breached the Docker Hub user database. Around 5% of Docker Hub users were affected by the compromise, allowing threat actors to collect usernames, passwords, and credentials to repositories like GitHub, GitLab, and Bitbucket (where users store their code).
  • Container image vulnerability exploitation: Using vulnerable container images can lead to a wide range of issues. It can enable malware installation that provides attackers access to the host kernel. We have seen cryptocurrency miner-infected rogue containers embedded in community docker images before, which can happen again.
  • Network-related threats: While containers may be self-contained, they can talk to others within a network. As such, a compromised container can spread malware to others. Also, Internet-connected containers are prone to the same threats that affect computers, including distributed denial-of-service (DDoS), Structure Query Language (SQL) injection, and cross-site scripting (XSS) attacks.


Container security requires a comprehensive approach. Organizations need to address all container users’ needs and that their approach can be automated to ensure fast and secure application delivery. In sum, effective container security means protecting all setup components from the threats discussed above.