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What is the Citrix Spray Attack?

A “Citrix spray attack” is a cyberattack targeting Citrix NetScaler appliances, leveraging a method known as password spraying.  In this technique, attackers attempt to gain unauthorised access to multiple user accounts by testing a small set of commonly used passwords across a large number of accounts.  Unlike traditional brute force attacks that focus on cracking a single account, password spraying minimises detection by avoiding account lockouts, enabling attackers to evade security measures and potentially gain access to sensitive corporate networks and data.

Key Points About Citrix Spray Attacks

Target:

These attacks primarily focus on Citrix NetScaler appliances, widely used for load balancing and application delivery.

Method:

Attackers employ password spraying, testing a limited number of common passwords across many accounts instead of brute forcing one account with multiple password guesses—which causes the account to be blocked.

Why It’s Effective:

By using only a few password attempts per account, attackers can avoid triggering account lockout policies and other detection mechanisms.

Potential Consequences:

Successful attacks can lead to unauthorised access to sensitive systems and data and could enable lateral movement within the organisation’s network.

Additionally, attacks that don’t result in a successful compromise can still cause significant disruption to network performance via the added traffic from the attack itself, and from users having their accounts locked.

How to Defend Against Citrix Spray Attacks

Defending against password spraying requires a proactive, multi-layered security strategy.  Here are key recommendations:

1. Implement Strong Authentication Measures

While strong, unique passwords are important, they are not sufficient on their own.  Swivel Secure recommends enhancing your security with the following factors (or even replacing passwords entirely):

  • Multi-Factor Authentication (MFA): Add an extra layer of security by requiring additional verification factors, such as a One-Time Password (OTP) or a push notification.
  • Risk-Based Authentication: Dynamically adapt authentication requirements based on factors such as login behaviour, device type, or location.

2. Adopt a Multi-Vendor Security Model

A diverse security approach can limit the risk of privilege escalation and lateral movement.  To reduce exposure, avoid relying on a single-platform environment.

3. Regularly Assess Your Password Security

Conduct regular password risk assessments to identify vulnerabilities and enforce stronger policies.  This proactive approach can help prevent attackers from exploiting weak credentials.

Swivel Secure: Your Partner in Authentication Security

At Swivel Secure, we provide a range of user-friendly authentication options designed to mitigate brute force and spray attacks.  Our solutions include MFA, OTPs, and risk-based authentication, enabling you to strengthen your security posture effectively and efficiently.

Beyond providing robust authentication tools, we advocate for a comprehensive, multi-layered security strategy tailored to your organisation’s needs.

Take Action Today

Don’t wait for an attack to test your defences.  Contact us today to discover how Swivel Secure can help protect your organisation from emerging threats like Citrix spray attacks.

Stay ahead of the attackers.  Stay secure with Swivel Secure.