Technical Advice

Citrix NetScaler Zero-Day: What IT Leaders Need to Act On

On 27 August, Citrix confirmed a critical new zero-day in its NetScaler ADC and Gateway appliances. Tracked as CVE-2025-7775, the flaw is already under active exploitation. The US Cybersecurity and Infrastructure Security Agency (CISA) immediately placed it on the Known Exploited Vulnerabilities list, giving federal agencies just 48 hours to patch. While no equivalent mandate has yet been issued in the UK, the risk is clear and pressing: this is an edge vulnerability with real-world attacks already underway.

NetScaler appliances are designed to provide secure remote access, load balancing and application delivery. In practice, they often sit directly on the network perimeter, bridging internal services to the wider internet. That architecture makes them highly attractive targets. In 2023, the so-called CitrixBleed vulnerability was exploited at scale, leading to ransomware outbreaks and significant disruption across multiple sectors. CVE-2025-7775 carries the same potential.

For IT leaders, the response must be swift and uncompromising. Citrix has already released patches, and there are no alternative mitigations. Any delay increases the likelihood of compromise, with attackers actively scanning for vulnerable appliances. The lesson from past NetScaler exploits is that adversaries move quickly—often within hours of disclosure. Organisations that patch late are the ones that suffer breaches.

Patching alone, however, is not enough. Security teams should assume that unpatched systems may have been probed or compromised in the weeks leading up to the disclosure. That means reviewing logs for unusual administrative access, unexpected configuration changes or the presence of webshells. Particular attention should be paid to activity dating back to early August. If suspicious activity is detected, incident response should be escalated immediately.

There is also a leadership message to be conveyed. IT leaders should brief boards and senior stakeholders with clear language: this is not an abstract technical issue but a live business risk. A compromised NetScaler appliance provides attackers with direct access to the enterprise environment, from which they can move laterally to sensitive systems such as domain controllers, ERP platforms or customer databases. The reputational, financial and regulatory consequences of such an intrusion are significant.

The incident also highlights a broader governance challenge. NetScaler devices are not commodity endpoints—they are critical control points at the edge of the enterprise. Their resilience should be treated as a leadership concern, with patching regimes, monitoring, and segmentation integrated into ongoing resilience planning. This is not simply about emergency fixes but about ensuring perimeter appliances are managed as strategic assets.

The wider lesson is that organisations cannot afford complacency with edge infrastructure. Vendors continue to disclose serious flaws at regular intervals, and attackers will exploit them within days if not hours. IT leaders should treat this latest Citrix zero-day as both a call to immediate action and a reminder of the need for structured, proactive resilience strategies.

The bottom line is clear: apply the patches without delay, investigate for potential compromise, and ensure stakeholders understand the seriousness of the threat. CVE-2025-7775 is not a theoretical weakness but an exploited vulnerability at the perimeter. Addressing it swiftly is the difference between resilience and compromise.

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Phishing remains the single biggest threat vector for most organisations—yet it’s also one of the easiest risks to mitigate. That’s why regular, well-designed phishing training has become a staple for IT leaders. But does it really work, and how do you make sure your programme delivers real results?

Why Phishing Training Works

• It builds muscle memory: Regular exposure to simulated phishing emails helps staff spot the signs before they click.
• It raises awareness: Even non-technical users become more sceptical and cautious with suspicious messages.
• It creates positive peer pressure: When staff know they’re being tested, they tend to warn each other and ask questions.

How to Make It Work in Your Organisation

• Simulate real threats: Don’t just use generic, obvious phishing emails. Mimic the real lures your sector faces, and keep it fresh.
• Train regularly—but not predictably: Quarterly or monthly tests are best, but avoid making them routine or easily guessed.
• Focus on learning, not punishment: The goal is improvement, not embarrassment. Offer supportive feedback and extra training to those who slip up.
• Share results—but protect privacy: Report overall stats to the business, but avoid naming and shaming individuals.
• Tie it to broader security culture: Phishing awareness shouldn’t be a box-ticking exercise. Make it part of a wider security-first mindset.

The Bottom Line

Phishing training works best when it’s ongoing, relevant, and delivered as part of a positive, learning-focused culture. As a CIO or IT leader, it’s one of the most cost-effective ways to reduce risk—if you take it seriously and keep it evolving.

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Zero Trust has moved from buzzword to board agenda—but implementing it is another story. Here’s what IT leaders have learned from deploying Zero Trust in real environments.

What Works

• Clear asset inventory: Knowing exactly what you have is the foundation for strong authentication and network segmentation.
• Incremental rollout: Starting with high-value systems lets you test and learn before scaling across the organisation.
• Strong identity management: Multi-factor authentication (MFA) and identity governance deliver immediate risk reduction.

What Doesn’t

• Trying to do everything at once: It’s overwhelming. Focus on core processes and high-risk assets first.
• Ignoring user experience: Overly complex controls lead to workarounds. Balance security with usability.

Key Takeaways

Zero Trust is a journey, not a destination. Prioritise visibility, strong identity, and staged rollouts for best results.

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With more data and services moving to the cloud, vendor risk management is now a board priority. Here’s how to stay ahead of the risks.

Map Your Vendor Landscape

• Catalogue all third parties, not just “critical” ones.
• Track where your data resides, who can access it, and for what purpose.

Set Clear Expectations

• Use contracts and SLAs to enforce security requirements.
• Don’t be afraid to ask for certifications, regular reporting, and proof of controls.

Monitor, Review, Improve

• Vendor assessments aren’t “set and forget”—review regularly, especially after any incidents.
• Have an exit plan in case a supplier’s risk profile changes.

The right approach to vendor risk lets you move faster, without losing control.

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Moving from a hands-on IT role to a leadership position is both exciting and daunting. Here’s how to start preparing—before you’re offered the job.

Develop “Soft” Skills

Great IT leaders are great communicators:

• Practice explaining technical issues to non-technical colleagues.
• Get comfortable presenting, even in small groups.

Understand the Business

Show you care about the “why” behind IT decisions:

• Volunteer for cross-department projects.
• Attend business meetings.
• Learn the language of finance and risk.

Build a Network

• Seek out mentors—inside and outside IT.
• Join leadership forums and professional bodies (like the BCS or ISACA).

Take on Leadership Tasks

• Ask to run a project, lead a stand-up, or manage a small team.
• Experience, even on a small scale, matters.

Leadership isn’t a job title—it’s a habit you build, one step at a time.

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Bridging the gap between technical detail and business impact is a core CIO skill. Here’s how to make cyber and IT a board-level priority.

Focus on Business Impact

Frame cyber risks in business terms:

• “If this system is down, these services stop, and revenue is at risk.”
• Use plain English, not acronyms.

Quantify Risk Where Possible

Boards respond to numbers:

• Give clear metrics (e.g. likely cost of a breach, time to recover).
• If you can’t measure it, give a well-reasoned estimate.

Be Honest, But Propose Solutions

Don’t sugarcoat challenges, but always bring an action plan:

• “We’re seeing increased ransomware attempts, and here’s how we’re reducing our exposure.”

Make IT Part of Strategy

Position IT and security as enablers of business growth and continuity, not just cost centres.

The board doesn’t need to be technical. They need to be informed and ready to act.

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Modern cyber risks demand more than just technology—they demand people who think and act securely by default. As IT leaders, we must champion a culture where security is everyone’s responsibility, not just the domain of the infosec team.

Start With Leadership

A security-first culture starts at the top. Board members and execs must be seen to value cyber hygiene and support new initiatives, even when they require business change.

Make Training Real (and Relatable)

Mandatory annual e-learning rarely moves the needle. Instead:

• Bring security scenarios to life with regular, short “micro-drills”
• Run phishing simulations and open Q&A sessions
• Reward those who flag suspicious activity

Embed Security in Daily Processes

Security shouldn’t be a blocker—make it easy to do the right thing. Bake security reviews into procurement, onboarding, and even performance objectives. Make secure practices part of “how we do things here.”

Celebrate Successes, Learn from Incidents

Highlight wins, such as thwarted phishing attempts or staff who’ve reported genuine threats. When things go wrong, focus on lessons learned, not blame.

Security is a team sport—let’s play to win.