The Six Layers of SaaS Security

June 6, 2024 at 8:00 am by Amanda Canale

When it comes to Software as a Service (SaaS), security is paramount. The architecture of SaaS applications involves multiple layers, each requiring its own set of security measures. Understanding these layers and how they interconnect helps build a robust defense system.

This is by no means an exhaustive list, as the cybersecurity landscape is constantly changing to mitigate the ever-evolving risks that come with storing sensitive information. This is simply a general overview of just some of the various aspects of SaaS cybersecurity that, when in combination with other methodologies such as SaaS Security Posture Management (SSPM), can provide applications with the security they critically need.

Layer 1: Cloud Security

The very foundation of SaaS security starts with the cloud. As the first line of defense, if the cloud is compromised, then the following security layers are subject to failure as well. It’s this key aspect that makes having proper cloud security measures in place so critical.

One aspect that some don’t often think about when picturing cloud security is the physical security of the data center. Physical barriers, surveillance and monitoring, access controls and visitor management, environmental controls, and in-house data decommissioning are all aspects of data center physical security that play a role in protecting these fortresses that safeguard the provider’s priceless assets.

Another crucial aspect of cloud security is adhering to compliance regulations. Since SaaS providers handle such high volumes of sensitive information, complying with the proper mandates and regulations allows them to avoid legal and financial consequences and mitigate risks while safeguarding both the data they’re storing and their reputation.

These are just two essential security measures that play a role in cloud security; other methods include data encryption, regular security audits, and a slew of others.

Layer 2: Network Security

Network security is the next critical layer, protecting the communication channels between users and the SaaS application, as well as between the different components within the cloud infrastructure. At its core, network security acts as the traffic cop between all communication channels. Firewalls, intrusion detection and prevention systems, secure VPNs, and encryption protocols are just a few key measures that can, essentially, prevent a traffic jam.

Another key method for providers to prevent a jam is by limiting access to untrusted sources and adopting a zero-trust model. The zero trust model is based on the assumption that the call is coming from both inside and outside of the house, meaning no entity should be trusted by default. Adopting this mentality and methodology requires providers to continuously verify user identities and device compliance, for example, through multi-factor authentication, before granting access to their resources, significantly enhancing security.

Other key network monitoring tools can help providers collect and analyze their network’s performance data to find any anomalies or suspicious activity, all in real-time. The further we go into the digital age, the more machine learning and artificial intelligence (AI) are increasingly being used to enhance these kinds of detections.

By being able to swiftly detect and address these traffic jams and anomalies, providers can mitigate the impact of potential threats and maintain the integrity of their network.

Layer 3: Server Security

Servers host not only the SaaS applications but the sensitive data of their users as well, making them pivotal to the overall security architecture.

Securing servers can include, but is not limited to:

  • Hardening the operating systems by disabling any unnecessary services and ports, ultimately reducing the surface area and entry points for attacks;
  • Limiting access for both users and processes alike so they only have as much access as needed to complete their function; and
  • Utilizing patch management software that keeps the server’s software and applications up-to-date for optimal streamlining reduces the risk of human error.

Additionally, adopting other security measures such as anti-virus software, intrusion detection systems, and secure configurations can also enhance the protection of servers from both external and internal threats.

Layer 4: User Access Security

Throughout this article, we’ve touched upon how controlling who can access the SaaS application, its infrastructure and components, as well as the collected data, is crucial to maintaining security. User access security involves implementing robust authentication methods, such as multi-factor authentication (MFA), and managing user privileges through role-based access controls (RBAC).

By regularly reviewing and updating user permissions, providers can ensure that only authorized individuals have access to sensitive data and functions. In tandem with stringent asset controls comes properly training these privileged roles about security best practices and potential threats to further enhance overall security.

Layer 5: Application Security

The application layer focuses on securing the SaaS software itself. At this layer lie the more intricate risks, often in the form of coding errors both internally and in any third-party components that may be used. Application security can include adopting secure coding practices, such as:

  • Input validation ensures that all inputs are validated and sanitized to prevent attacks and that only properly formatted data is being processed.
  • Output encoding mitigates cross-site script (XXS) attacks by converting data into a secure format that then prevents the browser from interpreting user-supplied data as part of the web page’s code. In layman’s terms, it prevents any interference with the web page’s intended functionality and/or appearance.
  • Error handling mechanisms can be used to prevent any sensitive information from being released through error messages. It allows providers to create custom error pages and log errors securely without being exposed, and more.

Again, these are just a few measures providers can take to ensure application security and maintain the integrity of their service.

Layer 6: Data Security

At the heart of SaaS security is the protection of data. That’s why we’re here! Data security is all about ensuring the confidentiality, integrity, and availability of data stored and processed by the SaaS application. Data security measures can encompass a lot of varying methods and methodologies, from all of what we’ve discussed so far in this article to encryption and backup recovery, data auditing and masking, compliance, and so much more.

To put it succinctly, data security is not a one-size-fits-all solution, nor is there a one-stop-shop for ensuring it. Data security is truly a multifaceted discipline that requires a robust approach, quite literally meaning all hands on deck.

However, there is one vital measure of data security that should always be a key ingredient in whatever security cocktail a SaaS provider concocts: creating and maintaining both a chain of custody and secure data decommissioning procedures.

A chain of custody is a detailed, documented trail of the data’s handling, movement, access, and activity throughout its lifetime that should only ever be managed by authorized personnel.

A secure data decommissioning procedure goes hand-in-hand with a chain of custody, as it is the data’s last stop and the documentation’s last box to check. The criticality of a secure data decommissioning procedure for safeguarding sensitive information cannot be overstated. When SaaS applications reach end-of-life or are moved to alternative locations, organizations must ensure that data is properly disposed of in accordance with industry regulations and best practices to ensure the data is effectively destroyed.

The Hidden Layer: Human Security

The human layer is an essential layer of SaaS security, but unfortunately, it is often overlooked. This layer recognizes that the people handling the data and equipment can be both its greatest asset and its weakest link. This layer encompasses robust security awareness training, a well-documented and maintained chain of custody, fostering a culture of security, and implementing policies that help guide secure behavior.

Routine training programs help educate employees on identifying phishing attempts, using strong passwords, and following best practices for data protection. Encouraging a security-first mindset helps create an environment where employees are vigilant and proactive about security.

By acknowledging and addressing the human layer, SaaS providers can significantly reduce the risk of insider threats and human errors, thereby strengthening the overall security posture of their applications.


In summary, SaaS security is not a one-stop-shop. There is no sure-fire, quick fix to ensuring the integrity of the provider and their efforts, but rather a comprehensive, robust, almost mix-and-match sort of approach that addresses each of these layers and puts data security at the forefront.

These measures not only protect the data itself but also build trust with users and comply with regulatory requirements. By implementing robust security measures at the cloud, network, server, user access, application, data, and human levels, SaaS providers can build resilient defenses against threats and ensure the protection of their SaaS environments.