Citrix NetScaler is a widely used Application Delivery Controller (ADC), that provides essential functions such as load balancing, application delivery, and security. It plays a vital role in the performance and security of many enterprise networks.

As cyber-attacks increase worldwide by almost 50% in Q1 2025 and businesses in the UK&I have reported an average of 58 cyber-attacks last year, which is nearly 2 a week. Cyber-attacks have also escalated not only in frequency but in both scale and sophistication, it is essential to ensure that NetScaler devices are correctly configured to minimise vulnerabilities and protect organisations.

As well as releasing frequent security updates for NetScaler devices, Citrix offers the following Security Advisory Configuration advice:

Update your NetScaler appliance to the latest Citrix firmware. This ensures you have the latest security patches to protect against known vulnerabilities and exploits.

2. Enforce strong, unique passwords and regular password rotation for all NetScaler accounts.

3. Access NetScaler management via HTTPS or a secure VPN and avoid using unsecured protocols like HTTP or Telnet.

4. Enable Multi-Factor Authentication (MFA) for NetScaler administrators accessing NetScaler configurations to add an additional layer of security beyond passwords.

5. Restrict admin access to trusted networks or devices using IP whitelisting or ACLs, to restrict administrative access to trusted networks or devices to authorised personnel only.

6. Disable unused NetScaler features, services, and outdated protocols (like older SSL/TLS or weak ciphers) to minimise vulnerabilities.

Enhancing NetScaler Security: Additional Precautions  

Beyond the essential security measures, additional steps can further strengthen NetScaler configurations. For organisations managing sensitive data or critical applications, these extra precautions are crucial in preventing data breaches and ensuring operational safety.

Server Hardening

Ensure virtual servers are properly configured and secured. Verify that SSL certificates are current, secure, and properly configured. Remove Legacy Programs such as outdated or unused programs and apps to prevent potential vulnerabilities. Regularly check for updated versions to ensure that the programs and apps are current.

Segregate Management and Data Traffic

NetScaler is enabling a new capability to separate management and data traffic across different interfaces, networks, and routing paths. 

The Management Plane is the part of the network used for administrative tasks — such as logging in to NetScaler for configuration, monitoring, or troubleshooting. It includes access via SSH, the web GUI, API calls, SNMP, and other system-level controls.

The Data Plane is where your actual application traffic flows. It handles load balancing, client-server requests, gateway services, and anything that your users or customers interact with.

Both planes serve very different purposes and ideally, they should never share the same path or be exposed to the same threats. This is an exciting new feature that Citrix is introducing.  You can read more about it here

Back Up NetScaler Configurations

Take regular backups of NetScaler configurations and store them in a secure location. If an outage or misconfiguration occurs, you can then quickly restore the NetScaler back to its previous functioning and secure state.

Citrix Alerts and Known Vulnerabilities

Application Delivery Controllers such as NetScaler have had some vulnerabilities identified in recent years, such as remote code executions and privilege escalation flaws. These incidents have emphasised the need for consistent patching and adherence to secure configuration best practices to protect NetScaler deployments.

Citrix regularly releases security bulletins and updates to address known vulnerabilities for NetScaler, helping you stay informed and protected. It is critical to stay informed about these advisories and apply suggested patches or mitigations promptly.

At Enterprise Solutions, we prioritise keeping our customers informed the moment we receive alert notifications, and ensure they stay up to date on upcoming security events and new features.

Boost your NetScaler Security

Improving NetScaler security is an ongoing process that demands constant vigilance, regular maintenance and updates to stay protected.

It is all too easy to adopt a “set it and forget it” approach with NetScaler devices but they should instead be treated as integral components of the overall security framework.

By adhering to the recommendations outlined in this blog, organisations can drastically reduce the risk of cyber threats targeting their NetScaler appliances and ensure optimal performance and confidentiality.

An organisation’s security depends on proactive measures and continuous monitoring. Vulnerability management should be prioritised along with robust authentication. As a Citrix Platinum Partner, Enterprise Solutions’ skilled team of Citrix engineers is ready to support your organisation to maintain and improve Citrix NetScaler security.

Our dedicated team of experts at Enterprise Solutions is here to guide you every step of the way. From installation to maintenance and patching, we provide tailored advice and hands-on assistance to ensure you stay secure and ahead of emerging threats using NetScaler’s security features and protect your infrastructure.

Contact our experts today – asktheexpert@enterprise-solutions.ie

Sources

• https://blog.checkpoint.com/research/q1-2025-global-cyber-attack-report-from-check-point-software-an-almost-50-surge-in-cyber-threats-worldwide-with-a-rise-of-126-in-ransomware-attacks/#:~:text=Cyber%20Attack%20Surge%3A%20In%20Q1,2%2C678%20and%202%2C664%20attacks%2C%20respectively 
• https://www.hiscox.ie/cyber-readiness-report-2024