What are Zero-day Vulnerabilities?
Imagine someone finds a spare key to your office that you didn’t know existed. There’s no alarm tied to it, no record of it and because you don’t know it’s there, you haven’t changed the locks.
You can think of zero-day vulnerabilities like that.
More specifically, they are undiscovered flaws in a device, application or operating system for which there is no vendor patch because the manufacturer doesn’t know they exist.
In other words, they’ve had “zero days” to prepare a response.
Attackers exploit these vulnerabilities to bypass security measures and wreak havoc on your IT environment before anyone realizes the threat exists.
Let’s examine how zero-day vulnerabilities are discovered, why they are increasing in volume and if there’s anything you can do to protect your organization.
How are Zero-day Vulnerabilities Discovered?
Attackers discover zero-day vulnerabilities through a combination of technical methods and luck.
It’s important to understand that every system, application or device has security gaps. There is no such thing as 100% secure. Given this, attackers will try to reverse-engineer software and hardware to find weaknesses that have yet to be discovered.
But it’s not just attackers. Large enterprises (Microsoft, Google, etc.) will pay security researchers to identify zero-day vulnerabilities in their own software before malicious actors can exploit them.
Why are Zero-day Vulnerabilities on the Rise?
Zero-day vulnerabilities were once reserved for the most high-stakes attacks. They were something you’d find as a plot point in a Hollywood thriller rather than a mainstream threat.
Today, not only is the number of attacks increasing rapidly, but so is the speed at which they occur.
According to cybersecurity firm Forescout Technologies, zero-day vulnerabilities increased 46% in the first half of 2025 compared to the same period in 2024.
But why are zero-day vulnerabilities on the rise?
One of the biggest drivers appears to be the expansion of technologies such as mobile, cloud and the Internet of Things. More systems and devices online lead to more software and hardware flaws that can be exploited.
Secondly, AI has accelerated the volume and learning curve of these attacks. The technical methods used to discover zero-day vulnerabilities can now be automated, enabling more discoveries in less time. Additionally, AI lowers the barrier to discovering and refining vulnerabilities, accelerating the pace of research and exploitation.
Zero-day exploits are scary and should be taken seriously. While you can’t fully prevent them, there are ways to protect your organization by reducing risk and limiting the damage they can do.
Zero-day vulnerabilities will become more prevalent as small businesses increasingly rely on technology. In fact, many attackers target small businesses because they often lack proper security systems.
How Do You Defend Against Zero-day Vulnerabilities?
There are a few ways to combat zero-day vulnerabilities.
Implement Next-generation Antivirus
Antivirus software is effective at scanning and removing known threats, but it can’t detect undiscovered ones.
That’s where next-generation antivirus (NGAV) steps in.
It’s a modern security approach that includes things like process behavior and machine learning to anticipate and prevent known and unknown threats. It aims to stop threats before they infiltrate your network.
Implement Endpoint Detection and Response
Endpoint detection and response (EDR) helps your IT staff or managed service provider respond to threats before they can spread to other parts of your network.
It also uses AI and machine learning to detect and remediate known and unknown threats.
It’s not a prevention tool, like NGAV, but it helps limit the burn radius once the fire already has started.
If NGAV is your first line of defense, EDR is your safety net that catches anything that slips through the cracks. They complement each other to provide a comprehensive security solution.
Strategy Implementations
The tools listed above help reduce damage, but you can implement security configurations that make exploits less effective.
- Patch management process: Your organization should maintain regular patching cycles so that, when an unknown vulnerability becomes known, you can fix the root cause.
- Least privilege access: Restrict access rights and permissions to the least amount necessary to safely operate.
- Network segmentation: Isolate your network into smaller subnetworks so attackers can’t move laterally.
Protect Your Organization’s Devices
Zero-day vulnerabilities will become more prevalent as small businesses increasingly rely on technology. NGAV and EDR are essential tools for any organization, as no target — regardless of size — is off-limits. In fact, many attackers target small businesses because they often lack proper security systems.
Let’s secure your business before the next threat hits. Don’t wait until a data breach or cyberattack to improve your organization’s security posture. Contact us today to schedule a consultation.
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