SharePoint Under Siege

A Strategic Response to CVE-2025-53770

The alerts hit the wire like a flash flood. On July 20th, CISA and Microsoft issued urgent guidance on a critical SharePoint vulnerability, CVE-2025-53770. The technical details are stark: a flaw allowing for Remote Code Execution. In plain English, it means an attacker can run their own code on your server, effectively taking control.

For any organisation using SharePoint, this is a code-red situation. SharePoint is often the central nervous system of a business—the vault where your "crown jewel" data, intellectual property, and sensitive collaborations are stored.

For businesses across the Benelux, a critical vulnerability in a core collaboration tool like SharePoint is not just a security issue—it's a direct threat to operational continuity and a significant challenge for maintaining compliance with regulations like NIS2 and DORA.

The immediate advice is clear: patch now. But in my line of work, the first alert is rarely the whole story. The real lesson isn't just about this single patch; it's about the dangerous, reactive cycle that so many businesses are trapped in.

The Reactive Trap: The Problem with a "Patch-and-Pray" Strategy

Every CISO knows the drill. A critical vulnerability is announced, and a frantic scramble begins. But this "patch-and-pray" approach is a losing game. Here’s why:

• The Patching Gap: The time between a vulnerability's disclosure and when your team can safely test and deploy the patch is a golden window for attackers. It can be days, weeks, or even months of critical exposure.

• The Un-patchable Reality: What about critical legacy systems that can't be patched? Or complex, customised SharePoint environments where a patch could break business-critical functions?

• The Sheer Volume: This is just one vulnerability. Security teams are drowning in a sea of CVEs, making it impossible to know what to fix first.

Focusing only on patching is like waiting for a house fire to start before you buy an extinguisher. True resilience is about having a strategy that protects you before, during, and after a vulnerability is announced.

A Resilient Defence: A Framework-Driven Approach

At Trescudo, we analyse these events through the lens of the NIST Cybersecurity Framework. It shows us that a resilient defence requires layers that go far beyond simple patching.

1. IDENTIFY: From Reactive Patching to Proactive Vulnerability Management
   You can't patch a vulnerability you don't know exists. This incident highlights the absolute need for a continuous Vulnerability Management program. Our approach, powered by Vicarius, moves beyond simple scanning. We provide an end-to-end platform that not only discovers and prioritises vulnerabilities based on real-world risk but also offers a revolutionary solution for the "un-patchable" problem.

2. PROTECT: Shielding the Vulnerability Before the Patch
   What if you could protect an application even if it's unpatched? This is where Patchless Protection™ comes in. Our technology can shield the vulnerable application in memory, blocking any attempt to exploit the known weakness. This closes your window of exposure instantly and gives your IT teams the breathing room to patch on their own schedule. Furthermore, a well-configured Web Application Firewall (WAF) can provide a "virtual patch," blocking malicious requests before they ever reach your SharePoint server.

3. DETECT & RESPOND: Assuming a Breach is Possible
   A resilient strategy always assumes the worst: what if an attacker does get through? This is where you need visibility. An AI-powered Extended Detection and Response (XDR) platform establishes a baseline of normal activity. If an attacker exploits the SharePoint vulnerability and starts moving laterally or exfiltrating data, the XDR system detects that suspicious behaviour and enables an instant, automated response, containing the threat in seconds.

From Theory to Practice: A Real-World Example

"We recently worked with a financial services firm in Luxembourg who faced this exact challenge with a different critical application. By implementing Patchless Protection™, we were able to shield their vulnerable servers within hours—long before a vendor patch was available. This gave their IT team the time to test and deploy the official patch without disrupting operations or accepting unnecessary risk.

The Takeaway: Build a Strategy, Not Just a Patching Cycle

The SharePoint CVE-2025-53770 is a symptom of a larger challenge. Relying on a reactive patching cycle alone is a recipe for a future breach.

At Trescudo, we help you break that cycle. We partner with you to build a proactive, resilient security program that combines a strategic framework with a curated portfolio of best-in-class technologies for vulnerability management, network security, and XDR.

Is your organisation ready to move from a reactive patching cycle to a proactive state of resilience? Let's have a conversation.

Sources: itpro.com, cisa.gov

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