What is an SSL VPN?
An SSL VPN is a Virtual Private Network (VPN) that provides secure remote access to internal resources using Secure Sockets Layer (SSL) or Transport Layer Security (TLS) encryption. The phrases SSL VPN and TLS VPN are used interchangeably, with the TLS encryption protocol being the direct successor of SSL.
SSL VPNs create encrypted tunnels over the internet via a web browser to provide safe and secure remote access for any type of device. They don’t require specialized client software, which makes them a quick and convenient enterprise VPN solution for connecting remote employees.
The Importance of SSL VPNs
With the acceleration of remote work and cloud adoption, you need to ensure employees connect to internal networks safely, without exposing sensitive data and systems.
Making your business resources accessible to off-site users opens the door to a number of cyberthreats, including:
- Man-in-the-Middle (MitM) attacks that intercept data sent and received over public networks.
- The use of insecure public WiFi networks empowers a range of attack vectors, including MITM attacks, traffic spoofing, DNS spoofing, and evil twin attacks.
- Attackers exploiting weak authentication processes to gain unauthorized access to sensitive data and business systems.
These attacks can lead to significant network breaches, non-compliance, and reputational damage.
How SSL VPN Works: Encryption, Authentication, and Tunneling
An SSL VPN uses the SSL/TLS protocol to create a secure, encrypted tunnel over the internet, enabling users to access internal network resources from anywhere.
While we have focused on clientless SSL VPNs, this is one of its two primary deployment types.
SSL Portal vs. Tunnel VPN
Let’s now compare SSL portal VPN and SSL tunnel VPN:
SSL Portal VPN
SSL portal VPN, also known as a clientless SSL VPN, offers secure access through a web-based portal on a compatible browser.
Users authenticate via their browser and are presented with an interface linking to specific internal resources.
They offer fast and easy deployment with no client installation needed, and are ideal for web-based applications and short-term users. But, SSL Portal VPNs provide limited access compared to other technologies and only support browser-accessible resources.
SSL Tunnel VPN
In contrast, an SSL tunnel VPN establishes a deeper level of connection. Sometimes called an SSL network extender, this type of SSL VPN requires a lightweight client or browser plugin to create a full SSL-encrypted tunnel from the user’s device into the network. This provides:
- Full access to internal networks
- Encryption for all traffic (not just browser traffic)
- More flexible connectivity
The trade-off is a more complex setup due to the client or plugin and higher bandwidth consumption.
Which One to Choose?
Choosing the right type of SSL VPN depends on your organization’s needs.
If you’re aiming for ease of deployment and convenience, a clientless SSL VPN may suffice. But if your users need deep access into the network, a Tunnel-based SSL VPN is more appropriate.
Key Features of SSL VPNs
Here are the key features of SSL VPNs:
- Remote access: SSL VPNs enable remote users to connect to the network and access resources from anywhere with an internet connection.
- Web-Based Access: With the SSL/TLS protocol built into most web browsers, SSL VPN remote access eliminates the need for separate client software. However, some SSL VPN implementations utilize client software for broader access.
- Ease of use: The browser-based interface makes clientless SSL VPNs easy to deploy and manage across a wide range of devices.
- Strong Encryption: SSL VPNs provide strong encryption to protect sensitive data in transit and prevent unauthorized access.
- Access controls: Administrators can define specific SSL VPN remote access policies, allowing users to access only the resources they need rather than the whole network.
Authentication: Organizations can implement robust authentication procedures, including the use of Multi-Factor Authentication (MFA), SSL VPNs, and biometric features.
Step-by-Step Guide to SSL VPN Connections
Here is a general guide to SSL connections. The specifics of each step may vary with each SSLP VPN implementation.
- Initiating an SSL VPN: The process begins when the user launches a VPN client or visits a secure web portal, depending on the type of SSL VPN.
- Authentication: The user enters login credentials to prove their identity and prevent unauthorized users from accessing business resources. These credentials are usually a username and password, but MFA can significantly improve SSL VPN security. MFA SSL VPN implementations use a secondary factor, such as an SMS code sent to a secure device, to prove the user’s identity.
- Encryption: After authentication, the SSL VPN client or browser establishes a secure connection using SSL/TLS protocols. This involves an SSL handshake to determine the encryption parameters and create the tunnel. Cryptographic keys are exchanged, and the server’s SSL certificate is verified to confirm its identity.
- Access: Once the encrypted tunnel is created, data can be safely transmitted to provide the user access to internal business systems. Requests are sent and received, exchanging data as if the user were inside the corporate network. The access level depends on how the SSL VPN is configured and whether it’s operating as a portal or tunnel.
Termination: When the session ends, the tunnel is closed. This terminates the connection and prevents further access until re-authentication. SSL VPN best practices recommend enforcing session timeouts, idle disconnects, and logging for additional protection.
IPsec VPNs vs. SSL VPNs
While both SSL VPNs and traditional VPNs, such as Internet Protocol Security (IPsec) VPNs, provide secure remote access and encrypt sensitive data, they differ significantly in how they operate. Understanding the core differences between SSL VPN vs IPsec is essential for selecting the right remote access solution for your organization.
- IPsec VPNs offer robust, full-device encryption and broad access that is ideal for users requiring full network capabilities and who work primarily with internal systems. But, the complexity of deployment and maintenance can make them less suitable for some organizations.
- SSL VPNs are lightweight and have a flexible access model. Their ability to provide secure access to specific apps and eliminate the need for dedicated software makes them a cost-effective, scalable choice, especially for organizations embracing cloud-native operations.
Core Differences in Operation
Here are the core differences in operation:
- Traditional IPsec VPNs encrypt all network traffic between the user and the network by operating at the network layer (Layer 3) of the OSI model. They use different protocols to create a secure link between the user and the business network.
- SSL VPNs work at the application layer (Layer 7) and are often clientless, so users can access it through any modern web browser, without any additional software. They establish a secure, SSL/TLS-encrypted tunnel between the browser and the internal server, protecting only the traffic that flows through that session.
Security, Authentication & Access Control
Here are the core differences in security, authentication, and access control:
- IPSec VPNs, by operating at the network layer, provide extra layers of security compared to SSL VPNs. Additionally, these VPNs encrypt your entire network traffic rather than only your web traffic.
- SSL VPNs security can define access down to individual apps or services to limit user privileges and reduce risk. MFA SSL VPN implementations also improve security by requiring more robust authentication procedures for each session.
Network Access
SSL VPNs enable access to specific sites and applications within your internal network.
While this provides less access than a traditional VPN, it offers benefits in specific scenarios. For example, employees or contractors who do not require access to the whole network.
Implementation
Now let’s compare the implementation:
- Traditional IPsec VPNs are more difficult and expensive to deploy at scale. They require VPN software and often hardware appliances, and provisioning each user requires significant IT involvement. Depending on the IPSec VPN used, you may also have to maintain licenses, manage software updates, and train users.
SSL VPN remote access simplifies deployment. Since most users already have a browser installed, clientless SSL VPN connections can be made almost immediately, significantly reducing the complexity of deployment for both users and administrators.
Deploying an SSL VPN within a SASE/SSE Framework
SASE and SSE frameworks aim to unify network and security services in the cloud for secure, identity-aware access regardless of user location. Within this context, SSL VPN remote access can continue to play a role, especially when implemented with best practices that align with SASE principles.
In highly distributed, zero trust environments, a SASE SSL VPN provides granular, encrypted access to internal applications. Unlike traditional VPNs, SSL VPNs are optimized for secure, browser-based sessions, making them ideal for organizations prioritizing scalability, agility, and a seamless user experience.
When implemented properly, following SSL VPN best practices, the technology can also complement cloud security services like:
- Cloud Access Security Brokers (CASBs)
- Zero Trust Network Access (ZTNA)
- Firewall-as-a-Service (FWaaS)
This allows for unified policy enforcement while maintaining flexible access for employees, contractors, and partners.
Top 6 Best Practices: Configuration, Monitoring & Access Policies
To safeguard your network and users during SSL VPN remote access, you must implement proven SSL VPN best practices for configuration, ongoing monitoring, and access policies. These strategies ensure that your SSL VPN remains resilient, compliant, and aligned with your broader cybersecurity posture.
Configuration SSL VPN Best Practices:
- Enforce Multi-Factor Authentication: MFA SSL VPN enforcement and adding a second layer of authentication are effective ways of preventing unauthorized access
- Strong Encryption: Use the latest TLS protocols to ensure SSL VPN security
Monitoring & logging SSL VPN best practices:
- Enable Full Session Logging: Track and centralize all user logins, access attempts, and data transfers
- Audit Regularly for Configuration Drift: Configuration changes over time can weaken your security. With regular audits, you can ensure that SSL VPN security and performance remain aligned with best practices
Access policy SSL VPN best practices:
- Role-Based and Application-Specific Access: Configure SSL VPN tunnels to specific applications or services based on the user’s role
- Review and Revoke Access Regularly: Automatically expire credentials for temporary users like contractors to avoid lingering exposure
Implementing these SSL VPN best practices allows your remote access strategy to remain secure, adaptable, and prepared for evolving threats. Whether used as part of a SASE framework or as a standalone access solution, the success of an SSL VPN depends on how it is implemented and maintained throughout its use.
The Pros & Cons of SSL VPNs
Let’s now take a look at the potential benefits and drawbacks of using SSL VPNs in your organization.
Advantages of SSL VPNs
- Streamlined deployment
- Simplified user experience
- Reduced administrative overhead
- Application-specific access controls
- Broad compatibility
- Highly customizable and flexible
Disadvantages of SSL VPNs
- Security controls are restricted to browser traffic
- Limited access coverage
- Risks associated with users forgetting to terminate browser sessions
A Convenient Way of Remote Work
The primary benefit of VPNs for enterprises is providing a secure, encrypted tunnel with robust authentication procedures to connect external, off-site users and internal business networks. SSL VPNs are a popular type of VPN for secure network access, providing a convenient way of remote work from any device with a web browser.
- Traditional VPNs require preconfigured clients and deeper system integration.
- Clientless SSL VPN solutions let users access internal business networks without any software installation.
This approach allows for secure, flexible, and clientless access through any modern web browser. The result is reduced complexity and faster deployment.
This makes SSL VPNs ideal for mobile employees, temporary contractors, and rapid remote work enablement.
Enabling Bring Your Own Device
SSL VPNs also help enable Bring Your Own Device (BYOD) policies, as staff don’t have to download and install dedicated VPN software on their personal devices.
While primarily used for secure remote access, SSL/TLS encryption protocols can also provide site-to-site connectivity. With hybrid VPN capabilities, SSL VPNs offer a fast and easy-to-set-up method for encrypted connectivity between business locations.
But, keep in mind that SSL VPN security and performance are outperformed by other technologies.
Stay Secure with Remote Access VPN and Harmony SASE
Check Point offers a range of remote access capabilities, including its Remote Access VPN and Harmony SASE Platform.
With both IPSec and SSL VPN services available, Check Point’s Remote Access VPN offers both full access to the corporate network with a VPN client or fast and easy-to-implement web-based access. Plus, you can manage all your security gateways from a single, unified console. Learn more by downloading the Check Point Remote Access VPN datasheet and discover the simple and secure future of remote work.
Alternatively, to understand a more comprehensive security and networking framework, talk to an expert about Harmony SASE and what it can do for your organization.
