There are many security benefits that come from SDN architecture if designed and implemented properly. Just some of the ways that SDN hardens network security include:
- Prevention of DDoS attacks through its separation of data and control planes
- SDN firewalls that can be programmed with policies that provide granular, agile and immediate control over network traffic for design of sophisticated detection algorithms
- The ability to quickly identify intrusions and limit their reach and impact across the network
- Major reductions in false positives that save time and resources in network security protocols
- The ability to segment parts of the network in near real-time to isolate and quarantine malware, stop breaches, and prevent them from spreading across the network
Besides the centralized control of SDN allowing easy and response driven network programmability, it also sets the stage for the potential introduction of new security vulnerabilities to SDN network architecture. This is because the SDN controller sits at the heart of the agility and security possibilities of the architecture. The controller becomes a potential single point of failure where major vulnerabilities can be “baked in” without proper network design considerations.
How Attackers Could Compromise the Controller
From a security point of view, the separation of control and data planes at the heart of SDN is what provides the programming agility and vast network security improvements. At the same time, the SDN central controller, which is the catalyst for that agility, poses the greatest security vulnerability. This single point of control can be the ideal attack surface that can potentially give a hacker total control of the network.
By compromising the controller, an attacker can:
- Produce false network data and start other attacks on the entire network
- Insert or modify flow rules in the network devices, which would allow packets to be steered through the network to the attacker’s advantage.
- Launch sniffing and man-in-the-middle attacks to intercept, capture, and analyze network communication information by taking advantage of unencrypted communications to intercept traffic from and to a central controller
- Impersonate a controller/application, to gain access to network resources and manipulate the network operation
- Gain control of the communication path to flood the controller with packets requiring a flow rule decision and render it unavailable for legitimate users (DoS attack)
These are some of the primary ways vulnerabilities can be introduced without careful design of the SDN architecture. In the upcoming section on making the most of SDN security possibilities, we provide specific ways that all of these vulnerabilities can be addressed in the SDN architecture design and implementation process. Before discussing the remedies to these challenges, there are other places within the SDN architecture that can be potential vulnerability sources.
Application Manipulation and API Exploitation Vulnerabilities
in SDN Architecture
SDN can also be vulnerable to attacks in the application plane that can cause malfunction, disruption of service, or data eavesdropping. A poorly designed application can also introduce vulnerabilities to the system.
APIs within SDN architectures can have vulnerabilities that can give attackers the ability to extract network information or stop network flows. Side channel attacks on the data plane can give attackers the information to redirect traffic flows and allow eavesdropping. The amount of time it takes to establish a new network connection can tell attackers if there are flow rules in place.
All of these vulnerabilities are preventable, but they require a level of knowledge most networking specialists still lack as SDN continues to evolve and grow in adoption. Fortunately, there are numerous ways to avoid the security challenges of SDN while maximizing the security and agility benefits it can bring an organization.
Making the Most of SDN Security Possibilities
New and emerging technologies like SDN are sure to transform networking, but new technologies also bring vulnerabilities. In the case of SDN, those vulnerabilities are a product of a lack of knowledge in proper design and implementation. Consequently, all of the challenges can be avoided to provide all of the benefits that this network architecture can bring.
Based on the security vulnerabilities for the SDN controller and associated systems covered earlier, here are just some of the ways to make the most of SDN security possibilities:
- Roll out redundant controllers and strong encryption on the communication channels to stop controller attacks
- Put proper security mechanisms between every interface, component, and communication channel
- Use secure network elements with strong encryption algorithms to protect against side channel attacks and traffic diversions
- Keep servers updated with the latest patches to protect against application manipulation and API vulnerabilities
- Use rate limiting and packet dropping techniques at the controller plane to avoid DoS attacks
Network security policies and protocols are at the heart of maximizing SDN’s security benefits and avoiding its vulnerabilities. By failing to understand how best to implement them or the potential dangers of disabling network designs can introduce the seeds for serious repercussions for the network and the organization.
In an SDN-based network, it will be important for network operators to enforce the implementation of policies such as Transport Layer Security (TLS). Misconfigurations or incorrect use of security features can impact all layers in the architecture.
Success of SDN is Dependent on Proper Design
The benefits of enterprise network security and SDN are growing by the day with most networking professionals understanding that SDN represents the future of network possibilities. But to make the most of SDN, some security challenges must be avoided in the design, implementation, and modification phases within network centralized control and programmability features.
While SDN architectures are the future of secure and agile networking in the digital age, it requires a great deal of knowledge and planning. For example, there are a number of SDN rules that will set the stage for making the most of the architecture. With the support of a partner with expertise in SDN and traditional networking technologies like Acadia Technology Group, enterprises can set the stage for operations capable of meeting all operational needs.