Containerized deployments are on the rise, and for good reasons. They allow developers to deploy applications quickly and reliably by packaging them into self-contained, portable units of code. Kubernetes and Docker are becoming the go-to duo for deploying and managing containers. Together, they make it easier to build scalable digital services across different cloud environments.
It is predicted that by 2025, over 85% of companies will be using containers for production apps—which is a huge jump from just a few years ago. However, with containers, come vulnerabilities as they can sneak into containers, just like they can into any software.
Simply put, as more teams adopt container-based software, the responsibility for container security scanning is becoming a key part of the developer’s role to ensure everything stays secure. This blog will help developers in your organization understand the importance of container vulnerability scanning, how to do it, and best practices that can be followed in 2025 to ensure they are operating in a secure environment.
What Is Container Vulnerability Scanning?
Vulnerabilities can stem from various sources such as software inside containers, how they interact with the host OS, or even the networking and storage settings. Plus, issues can come from parent or base images your containers rely on.
Sometimes, a container is built on a publicly available image with known vulnerabilities, especially if you didn’t get it from a verified source. Even trusted images can have their own problems.
Container vulnerability scanning is a critical process to identify and address potential security weaknesses within containerized apps. It involves examining the container’s components, including the base image, application code, and dependencies, for known vulnerabilities or exploitable flaws.
Common Container Vulnerabilities and Their Impact
When it comes to container security, it is important to recognize the various types of vulnerabilities, especially those listed as Common Vulnerabilities and Exposures (CVEs) by organizations such as MITRE and the National Vulnerability Database (NVD).
1. Base Image Vulnerabilities
A lot of containers are built from base images that might have vulnerabilities. Using outdated or unpatched base images is pretty common, and these can have known security flaws that hackers could exploit.
A well-known example is the Heartbleed Bug, a critical vulnerability in OpenSSL that affected many applications, including those running in containers. The container vulnerability scanner checks these base images against known vulnerability databases, like the CVE list, to identify any outdated or compromised components.
2. Application Code Vulnerabilities
Remember Log4Shell? It was a flaw in a popular Java library, Apache Log4j 2, that let attackers run any code they wanted on vulnerable systems. Imagine hackers taking control of your entire app.
Application vulnerabilities are weaknesses in the code that hackers can take advantage of, whether it’s due to poor coding, misconfigurations, or outdated libraries. When these are present, they can lead to big issues, like data breaches or unauthorized access.
3. Dependency Vulnerabilities
Software projects usually rely on third-party components like external libraries and open-source code. These dependencies can introduce their own problems. In fact, a study by Black Duck found that 84% of apps have at least one vulnerable dependency! This risk is such a big deal that it’s made it onto the OWASP Top 10 list of security risks. With a prevalence score of 3 out of 3, it’s something many developers deal with, which just shows how important it is to keep an eye on your dependencies.
4. Container Runtime Vulnerabilities
A big risk with containers comes from the shared kernel model, where multiple containers on the same host share a single OS kernel. If one gets compromised, it could affect the others or even the host, leading to serious security breaches. Plus, configuration errors can add to these risks. Common mistakes include accidentally exposing ports to the internet or having weak authentication. For example, the Log4Shell vulnerability in Kubernetes allowed attackers to execute arbitrary code, giving them ways to gain unauthorized access or disrupt services.
5. Supply chain attacks
Attackers can inject malware into popular images and gain access to systems using them. A report by Chainguard found that one in four container images analyzed contained malicious code.
Supply chain attacks happen when hackers find ways to insert malicious code into software or compromise network components. These attacks target the process of building and distributing container images. They also look for vulnerabilities in the supply chain—like an app or an update—and exploit those weaknesses to gain access to critical digital resources.
One of the challenges with supply chain attacks is that the products being compromised often come from trusted vendors. This trust makes it easier for attackers to sneak into their targets’ systems. Ironically, the updates that are meant to fix security issues can sometimes be the entry point for these attacks, as hackers exploit the trust users place in them.
Importance of Container Vulnerability Scanning in 2025
While the primary goal of container image vulnerability scanning is to identify potential threats before they lead to data breaches or system compromises, its importance extends far beyond mere detection.
Here are other compelling reasons why container malware scanning is indispensable in 2025:
1. Enhanced Security Posture
Regular scanning helps identify vulnerabilities before deployment. The Sysdig 2023 report revealed that 87% of container images have high-risk vulnerabilities, underscoring the need for proactive scanning.
2. Compliance Adherence
Many industries require compliance with security standards such as NIST, PCI DSS, GDPR, CIS Benchmarks, and HIPAA. You must perform vulnerability scans to meet these requirements to avoid potential fines and legal actions.
3. Improved Incident Response
A Ponemon Institute study found that 63% of organizations struggle to act on the large number of alerts they receive, highlighting the challenges in vulnerability management. This emphasizes the need for effective scanning to prioritize and address vulnerabilities promptly.
4. Enhanced Reputation
Companies that prioritize security gain customer trust. A report by TrustArc revealed that 77% of consumers are more likely to engage with companies that have a strong reputation for data security.
How Container Vulnerability Scanning Works
Container vulnerability scanning involves identifying potential security threats within container images and their dependencies. Here is how it works to scan container images for vulnerabilities:
-
Layer-by-Layer Analysis
It involves analyzing a container image layer by layer. Each layer of a container image can include different software components, libraries, and configurations that might introduce vulnerabilities. The container security scanner examines these layers to detect any known security issues.
-
Use of Vulnerability Databases
Scanning tools compare the contents of the container image against databases of known vulnerabilities, such as the National Vulnerability Database (NVD) or the Common Vulnerabilities & Exposures (CVE) database. This helps identify vulnerabilities that have been publicly disclosed and documented.
-
Integration with CI/CD Pipelines
To ensure that vulnerabilities are detected early in the development process, container image vulnerability scanning is often integrated into Continuous Integration/Continuous Delivery (CI/CD) pipelines. This integration allows for automated scanning of images before they are deployed to production, helping to prevent insecure images from being used.
-
Reporting and Remediation
Once vulnerabilities are identified, the scanning tools provide detailed reports that categorize the vulnerabilities by severity. This information assists in prioritizing remediation efforts, such as patching or updating affected components.
-
Continuous Monitoring
Continuous scanning and monitoring are crucial for identifying new vulnerabilities in container images. This ongoing process ensures that emerging threats such as zero-day exploits or recently discovered security flaws in third-party libraries are detected and addressed promptly.
Common Challenges in Container Vulnerability Scanning
Container vulnerability scanning is crucial for identifying and mitigating security risks in containerized environments. However, several challenges can hinder its effectiveness:
1. Complex Dependencies
Containers often contain a complex stack of dependencies, including libraries and frameworks. Identifying and tracking vulnerabilities across these layers can be challenging, especially when containers use components from diverse sources.
2. False Positives and Negatives
Scanning tools may sometimes report vulnerabilities that do not pose a real threat (false positives) or fail to detect actual vulnerabilities (false negatives). Managing these inaccuracies requires additional verification processes, which can be resource-intensive.
3. Short Container Lifespan
The dynamic and ever-changing nature of containers really impacts observability, which is super important in the DevOps process. Unlike traditional monolithic applications, containers introduce unique challenges that can make monitoring feel a bit overwhelming.
One major issue is that each container generates its own logs and metrics. When a single application runs across multiple containers, collecting and analyzing data from each one can get pretty messy. It’s even trickier because containers can spin up and down so quickly, making it hard to keep track of everything consistently.
Plus, containers don’t exist in a vacuum. They’re part of a larger tech stack that includes servers, orchestration tools, load balancers, and API gateways. If there’s a hiccup in any of these areas, it can directly impact how your containers perform. This means it’s really important to connect the monitoring data from your containers with information from these other components.
On the security side, traditional tools like legacy antivirus software often struggle in container environments. They might not effectively catch security incidents when containers are constantly being created and destroyed.
4. Unsafe or Malicious Container Images
The widespread use of container images from public repositories raises security concerns. Not all images are vetted for security, and they may contain vulnerabilities or malicious code. Ensuring the integrity and trustworthiness of these images is extremely important.
Best Practices for Effective Container Security Scans
Implementing effective container security scans involves a few strategic practices that can significantly improve security coverage and reduce vulnerabilities. Here are some key best practices:
#1. Limiting Container Privileges
Docker containers run on what’s called “unprivileged” mode, which means they don’t have direct access to the host devices. This setup is intentional—it helps keep sensitive processes, like the Docker daemon, from running inside the containers and getting into trouble.
When it comes to security, the idea of limiting privileges is key. Both the Docker daemon and your containers should only have the access they absolutely need to the host system’s resources, like file systems and network connections.
A simple way to boost security is to always run your Docker daemon and containers as non-root users. This cuts down on the risk of privilege escalation and keeps your setup safer overall. You can also use user namespaces to map the container’s root user to a non-root user on the host, which adds another layer of protection.
Whenever you can, set your containers to use a read-only file system. This limits the chances of unauthorized changes and helps maintain your application’s integrity.
Don’t forget about security frameworks—they can enforce strong security policies on your host system, providing extra peace of mind. Practicing network segmentation is also a smart move, and helps control access and keeps things secure.
Tools like Kubernetes or Mesos can be helpful, as they support least privilege policies and make it easier to enforce security measures across all your containerized applications.
#2. Optimizing Docker Images with Multi-Stage Builds
Docker multi-stage builds are a fantastic way to streamline your image creation process. They help you create smaller, more efficient images while keeping your Dockerfile clean and easy to read.
Here’s why multi-stage builds are good instead of the traditional linear approach.
They make Dockerfile clearer and more maintainable. With multiple FROM instructions, you can easily define different stages in the build process, which helps you keep everything organized. Developers use multi-stage builds for better parallelization. You can build different stages at the same time, which speeds things up and improves performance overall.
Multi-stage builds let Dockers reuse layers from previous builds more effectively, leading to faster builds and less work for you. You can build on the output of earlier stages while discarding any unnecessary artifacts. This means your final images are not just smaller, but also cleaner and more secure.
#3. Integrate Security Early and Often
Taking a “shift-left” approach means bringing security into the software development process right from the start—and keeping it there throughout. It’s all about integrating security measures early and often.
One simple way to do this is by adding automated vulnerability scans to your version control system. That way, every time someone makes a code commit, it triggers a scan. This helps catch potential issues early on before they can snowball into bigger problems down the line.
#4. Automate Image-Scanning Processes
Integrating automated vulnerability scanning into your CI/CD pipeline is a smart way to keep your applications secure. By doing this, you ensure that every container image gets checked before it goes live.
For instance, you could set it up so that a scan runs automatically whenever a developer pushes code to the repository. If it finds any high-risk vulnerabilities, it can flag them right away and even block the build if there are critical issues. This approach not only helps catch problems early but also keeps your deployment process smooth and secure.
#5. Comprehensive Coverage
When you set up automated scans, it’s super important to make sure they cover everything in your container—from the base image all the way to the software layers and configuration settings you’ve added.
For example, you should regularly check each layer to catch outdated packages or any misconfigurations that could expose your application to risks. Taking this thorough approach allows you to spot vulnerabilities before they turn into bigger issues, helping to keep your application secure over time.
#6. Prioritize and Remediate Based on Risk
When it comes to managing vulnerabilities, it’s important to assess and categorize them based on their severity and potential impact. For instance, consider setting up a system that automatically flags high-risk vulnerabilities for immediate attention. This ensures that critical issues are addressed right away. Meanwhile, you can schedule lower-risk issues for updates at a later time.
#7. Educate and Train Development Teams
Regular training is essential for development teams to understand security best practices specific to container environments. These sessions could include detailed workshops on configuring Dockerfiles securely, managing sensitive data and secrets safely in container setups, and identifying common security pitfalls in container deployment and management practices.
#8. Continuous Monitoring and Response
Establish a continuous monitoring system for all deployed containers and create a clear protocol for responding to detected vulnerabilities. This might include real-time alerts to your security team whenever a potential security threat is detected, ensuring prompt action to mitigate risks.
SentinelOne Cloud Workload Security for Containers
SentinelOne’s Singularity Cloud Workload Security for Containers is designed to protect your containerized workloads from runtime threats like ransomware and zero-day attacks. With AI-driven threat detection and rapid response capabilities, it safeguards your environments across AWS, Azure, Google Cloud, and private data centers. Here’s a closer look at its key features:
- Instant Threat Detection: SentinelOne actively monitors container activities in real-time, using advanced threat detection to quickly identify any suspicious or malicious behavior. This means potential threats are caught early on before they can escalate.
- Swift Automated Response: The platform offers automated responses that react promptly to threats. If an issue is detected, it isolates and addresses it quickly, ensuring minimal disruption to your containerized applications.
- Comprehensive Vulnerability Management: With SentinelOne, organizations can continuously scan for and manage vulnerabilities in both container images and active containers. This proactive approach helps efficiently mitigate security risks before they become serious problems.
- Regulatory Compliance and Reporting: The platform includes robust monitoring and reporting tools that help organizations adhere to industry standards and meet regulatory requirements for container security, making compliance easier to manage.
- Seamless DevOps Integration: SentinelOne integrates smoothly with DevOps processes, embedding security at every stage of the development lifecycle—from the initial build to the final deployment. This ensures that security is a fundamental part of your operations, not just an afterthought.
Wrapping Up: Conclusion
As container usage continues to rise, it’s crucial to have strong security measures in place to fend off new threats. Adopting some of these best practices like integrating security early on, continuously scanning for malware, and educating your team can really help protect your containerized applications.
SentinelOne’s Singularity Cloud Workload Security for Containers offers comprehensive protection, featuring quick threat detection, automatic responses, and ongoing vulnerability management. These tools better your security setup but also help you stay compliant and fit seamlessly into your DevOps workflows, ensuring that security is always a part of the process.
If you’re looking to secure your container environments, consider scheduling a demo with SentinelOne to see how they can help!
FAQs
1. How does container vulnerability scanning differ from traditional security scans?
Container vulnerability scanning specifically targets containerized environments’ unique architecture and components, such as Docker images and Kubernetes pods, unlike traditional scans, which focus on physical or virtual servers.
2. What are the most common vulnerabilities found in container images?
Common vulnerabilities include outdated or insecure software libraries, misconfigured permissions or security settings, and the use of default passwords or exposed sensitive data.
3. How often should I perform container security scans?
It is recommended to perform security scans at every stage of the development lifecycle—during development, after updates or additions, and regularly in production environments—to catch new vulnerabilities.
4. Can container vulnerability scanners detect malware within container images?
Many container vulnerability scanners can detect malware by analyzing the signatures of known threats within container images, helping to prevent malicious software from being deployed.