Zero Trust SASE vs. SD-WAN

What Is SD-WAN?

Software-defined wide area networking (SD-WAN) connects offices, data centers, and users across locations by routing traffic over different connection types, avoiding costly private circuits like MPLS. It optimizes performance, reduces delays, and allows IT teams to centrally manage networks, prioritize applications, and monitor connections.

Despite these benefits, SD-WAN has limited ability to protect against modern cyberthreats, exposing organizations to added risk.

Read our full article: What Is SD-WAN?

Does SD-WAN Align with Zero Trust?

At its core, conventional SD-WAN was not designed with zero trust in mind. Zero trust subjects all entities to continuous verification based on attributes like their identity and security posture, even if they are already inside the network. SD-WAN, instead, implicitly trusts every connected user and device once it’s on the network.

SD-WAN improves connectivity and manageability, but fails to contain cyber risk. Many SD-WAN deployments end up with additional branch firewalls as a result, increasing cost and complexity. With that in mind, here are some of the specific ways SD-WAN fails to align with zero trust principles:

• Lateral threat movement: SD-WAN extends the corporate network to all offices for easy user-to-app communication. However, this extends trust between all locations—an infected camera in a branch office, for example, can reach apps in the data center, putting sensitive data at risk.
• Expanded attack surface: Every user, IoT device, or firewall in a branch becomes an attack surface. If a threat actor compromises any one of these, they compromise the entire network. This is how ransomware attacks start, and how they can spread so quickly inside an organization.
• Complex security: SD-WAN requires extra security tools like firewalls or virtual private networks (VPNs) to protect data. Using multiple tools increases costs, complexity, and administrative overhead.

What Is SASE?

Secure access service edge (SASE) is a networking and security framework delivered as a unified solution from the cloud. It combines:

• SD-WAN to connect locations and optimize performance by routing traffic efficiently
• Secure web gateway (SWG) to secure web traffic and block threats in real time
• Zero trust network access (ZTNA) to protect private apps with identity-based access controls
• Cloud access security broker (CASB) to control SaaS usage to reduce risks and ensure compliance
• Data loss prevention (DLP) to monitor data to prevent leaks and unauthorized access
• Firewall as a service (FWaaS) to inspect traffic and enforce threat prevention policy

SASE is attractive to today's digital-first enterprises as a way to simplify access management and improve scalability. However, because most SASE solutions depend on SD-WAN, they carry many of SD-WAN’s network-based security flaws.

Read our full article: What Is SASE?

Does SASE Align with Zero Trust?

SASE and zero trust both aim to improve security and make remote work and cloud adoption easier. But SASE alone doesn’t fully support the principles of zero trust if its architecture continues to focus on the network perimeter.

SASE typically connects users to networks that host the applications they need, against the zero trust principle of least-privileged access. Moreover, the standard SD-WAN that most SASE architectures use relies on perimeter-based firewalls. Even many ZTNA solutions—in spite of the "zero trust" moniker—grant users broad network access, rather than direct-to-app connections.

In these ways, SASE inherits the limitations of traditional architectures, even as it appears to be a modern framework. This leads to several areas of increased risk:

• A widened attack surface, exposing IP addresses to the open internet, where hackers can find and exploit them to access your network.
• Gaps in traffic inspection, especially encrypted traffic, because of the processing limitations of hardware-based and virtual firewalls.
• Potential for lateral movement, letting threat actors and attacks move across systems, putting more of the environment at risk.

To fully align with zero trust, SASE's SD-WAN connectivity cannot rely on networks. Instead, it needs to connect entities directly to the apps or services they need while enforcing granular, context-aware policies. Only then is it truly Zero Trust SD-WAN, the backbone of Zero Trust SASE.

What Is Zero Trust SASE?

Zero Trust SASE leverages Zero Trust SD-WAN to eliminate reliance on network-oriented trust models. Built on a complete zero trust architecture, it extends zero trust access to apps and data for all entities across branches, data centers, and clouds.

• Applies least-privileged access controls to all entities—users, apps, devices, and systems
• Inspects 100% of encrypted data traffic in real time with scalable, cloud-based tools
• Connects entities directly to the resources they need without extending networks or exposing IP addresses

Benefits of Zero Trust SASE

Zero Trust SASE delivers a safer and more efficient way to protect users, applications, and systems.

• Increase operational agility: Connect new sites or integrate acquisitions without complex, time-consuming network integration.
• Shrink the attack surface: Context-aware policies and IP address cloaking keep attackers from exploiting your systems.
• Gain full traffic visibility: Inspect 100% of encrypted and unencrypted traffic in real time to eliminate blind spots.
• Prevent lateral threat movement: Direct-to-app connections reduce lateral movement and block unauthorized access.

The Future of SASE and Zero Trust

Zero Trust SASE fills the gaps left in modern security by legacy SD-WAN, outdated network-based systems, and implicit trust. In their place, it uses precise, context-aware policies to reduce risk and provide secure, direct access to applications and resources.

Zero Trust SASE empowers organizations to simplify IT, protect ecosystems, and embrace secure digital transformation with:

• Cloud-first architecture: Consolidate IT processes, reduce complexity, and accelerate seamless cloud adoption across all locations.
• Full inline TLS/SSL inspection: Deliver real-time threat protection and prevent data loss across 100% of traffic, including encrypted data.
• Optimized traffic routing: Ensure fast, reliable access through global peering agreements with major service providers.
• Zero trust communications: Securely connect users, branches, and workloads without exposing networks to threat actors.
• Zero attack surface: Make IP addresses and sensitive infrastructure invisible to unauthorized users, preventing breaches before they start.