Recent industry research indicates that many container images used in production have high or critical vulnerabilities, prompting teams to rethink their software construction and operational strategies. Secure minimal container images are practical for integrating modern development methodologies while significantly reducing the number of known vulnerabilities. This article explores the risk patterns associated with traditional container images and discusses the reasons for the growing favor of leaner container images in DevOps security integrations.
The advent of containers has revolutionized software delivery and scaling, particularly in cloud-native environments where teams strive for rapid iterative releases. However, increased speed means decreased security. Recent vulnerability research shows that nearly 75% of container images contain critical or high-severity issues.
This leaves teams constantly overwhelmed with the never-ending circle of risk management and patching. With production environments increasingly scrutinized by attackers and regulators, many organizations look to reduce complexity and focus on the true requirements for securing deployments.
The Rising Cost of CVEs in Modern Infrastructure
The price of CVEs is alarming. A study from Sysdig on the security scans of container images shows that 87% of images are highly or critically vulnerable. This study analyzed telemetry from billions of containers and 100s of 1000s of applications across multiple organizations. It is important to note that, for the majority of the vulnerabilities the scans report, the vulnerable code is not part of the code that executes during runtime.
What is even more alarming is the volume of vulnerable code generated and the problems this causes for teams. Vulnerable code is not only present in applications, but also in the traditional base container images that include package managers, shells, and utilities that are not needed. All types of workloads experience this trend of ballooning vulnerability counts. Reducing the number of software and dependencies present is critical to minimizing the number of vulnerabilities present in an image.
The positive shift stems from an increased interest in secure containers that enclose a minimal set of components necessary for functionality. These container images start with a small base and add only what is needed for an application to function, thereby reducing the installed libraries and binaries that are scanned and flagged as vulnerable.
Why Traditional Container Images Are Expanding the Attack Surface
Generic container images are expanding the attack surface because they tend to be overly generic. That is, they include hundreds of other components that are unnecessary for the final product to be delivered. This is problematic for backend development because the containers will be deployed, and the software inside those containers will remain unused, but still be counted as vulnerable. Security analysts will still perceive the components as problematic and recommend remediating those assets, but in reality, that would be an unnecessary effort.
The fragmentation of workload means a variety of teams working in parallel, irrespective of whether or not the alerts relate to active attack vectors. This pattern fuels inefficiencies and can undermine the faith in automated scans as teams are unable to assess the quality of the alerts in relation to the actual risks to their systems.
Leaner images help by removing many of the nonessential pieces that contribute to this noise. When images contain what the application needs to operate, the teams are provided with relevant information and can narrow the list down to the relevant CVEs.
How Minimal Images Reduce Risk Without Slowing Development
Unlike other container images, Minimal container images take a different approach. Rather than commencing with a full distribution and removing portions, they start with a base that has only the essentials, then add a layer of what the application requires. This approach yields images that are significantly smaller, start much faster, and perform much better on vulnerability scans. Due to a smaller default software base, a smaller number of installed packages are prone to CVEs.
The effects that a smaller number of vulnerabilities has are greater than simply having better scanning metrics. DevOps can keep its velocity while tackling high-priority security issues due to the fact that it has a smaller number of vulnerabilities to scan and integrate. Smaller images require less storage and cross-cluster and cross-data-centre transfer.
A number of organizations have demonstrated the benefits of this approach in their security metrics over time. The more parts that are in an image, the more new vulnerabilities there tend to be. This is also true for upstream library updates. This reduces the ongoing maintenance overhead and ends the constant remediation cycles that teams have to perform for parts of the stack that are rarely, if ever, used.
The Compliance Pressure Facing DevOps and Security Teams
The requirement to maintain and document risk for software components and dependencies has reached an auditable level of detail for regulatory compliance. Auditors are unable to easily verify risk for numerous software dependencies found in container images. Streamlining images so that fewer components are included makes it easier for the auditor to provide validation.
Regulatory compliance in the areas of finance, government, and healthcare requires tracking of vulnerabilities and the ability to secure software supply chains. Compliance for software supply chains and risk management is supported by lean container images that help teams meet regulatory compliance requirements to clearly show what is deployed. This approach supports compliance with frameworks that focus on high software inventory and low risk.
