An Introductory Guide to Zero-Day Attacks and How to Prevent Them

An Introductory Guide to Zero-Day Attacks and How to Prevent Them

There are numerous forms of cyber security weaknesses and potential threats. On that note, companies have to secure their systems against these attacks in order to meet legal requirements and ensure the protection of their employees, clients, and confidential information. However, the zero-day attack is among the most widespread and challenging vulnerabilities to guard against.

An Overview of Software Vulnerabilities

In short, software systems are prone to having security weaknesses, which are unintended weaknesses or openings that could be exploited. For instance, there could be a gap in the system’s nginx ingress waf that enables a hacker to access highly sensitive information. As a result, software developers constantly monitor for these vulnerabilities. When they uncover one, they examine it, develop a solution to address it, and release the solution in an updated software version.

On that note, this brings us to discuss the definition of “zero-day”. The term “zero-day” (or “0-day”) refers to a situation where the security personnel are not yet aware of a software weakness and have had no time to address it with a patch or update. Meanwhile, the term “zero-day” is commonly linked with other terms such as vulnerability, exploit, and threat. To clarify:

  • A zero-day vulnerability is a previously unknown security weakness or software error that can be targeted by malicious third-party actors;
  • A zero-day exploit refers to the technique used by malicious actors to take advantage of the vulnerability to attack a system;
  • A zero-day attack happens when a cybercriminal launches malware to exploit the software flaw before the software creator has completely fixed the software vulnerability.

What Are Zero-Day Attacks and How Do They Work?

The term “zero-day vulnerability” refers to a danger of a previously unknown security vulnerability in software or computer applications for which a patch has yet to be released or the developers were not aware and did not have enough time to fix it. More specifically, the term “zero-day” highlights the fact that the software developer has only just become aware of the vulnerability and has no time to address it. In 2021, the Mandiant report found 80 zero-days exploited, which more than doubled the previous record set in 2019. As a result, this is why considering a zero-day flaw is crucial in designing secure and efficient applications.

To provide an example, a zero-day vulnerability can be comparable to an unlocked car door that the owner thinks is locked. Still, a thief discovers it is open, thereby allowing them to steal items undetected long before the owner notices.

Zero-day attacks can take the form of malware, spyware, adware, or unauthorised access to confidential user information. In the meantime, zero-day attacks can target a range of systems, including operating systems, office applications, hardware, firmware, open-source components, web browsers, and the Internet of Things (IoT). With that in mind, the potential victims of zero-day attacks can range from individuals using a vulnerable system to organisations and businesses, government agencies, and high-profile political figures.

On the other hand, the perpetrators behind zero-day attacks can have different motives, including financial gain for cybercriminals, political or social activism for hacktivists, corporate espionage for hackers spying on corporations, and cyberwarfare for countries attacking or spying on another nation’s cyberinfrastructure.

How Could Companies Recognise Zero-Day Attacks?

Zero-day vulnerabilities, which can arise from missing encryption, poor authorisation, algorithmic faults, bugs, or weak password security, among others, can be difficult to identify. As they are not known to the public until they have been discovered, information about them is limited. Consequently, businesses and organisations that fall prey to zero-day exploits may witness unusual traffic or suspicious-looking activities.

In the meanwhile, there are a variety of methods that can be used to detect zero-day vulnerabilities, including the following:

  • Consulting malware databases for reference, though it is also important to bear in mind that zero-day exploits are new and, thereby, often unknown to these databases;
  • Observing the interactions between incoming files and the existing software to determine if they might be malicious;
  • Employing machine learning to establish a baseline for safe system behaviour based on previous and current data. In essence, the greater the availability of data, the higher the reliability of the detection system;
  • Utilising a combination of different detection methods to generate more accurate results.

How Could Businesses Protect Themselves Against Zero-Day Attacks?

Protecting against the potential of a zero-day attack can be challenging as it can take various forms. Not to mention, any security vulnerability could be exploited as a zero-day if a patch isn’t released in time. Nevertheless, the good news is that companies could consider employing some of these steps to defend themselves against zero-day attacks:

Remain Vigilant

Although zero-day exploits are often not publicly announced, you can still be aware of potential threats by following the news in the technology industry as well as software vendor updates.

Keep the Software Systems Updated

Software developers work hard to release patches for vulnerabilities. With that in mind, it is significant to keep your systems updated by enabling automatic updates to ensure that your software is updated consistently.

Limit The Use of Software Applications

In essence, the more software you have, the more security vulnerabilities you will be exposed to. Therefore, the general best practice would be to limit the use of applications to the essentials.

Use Firewalls

Firewalls play a crucial role in protecting against zero-day threats. Other than that, having proper configuration would allow only necessary transactions, which may subsequently provide maximum protection.

Concluding Thoughts

In summary, zero-day attacks are a type of cyberattack that take advantage of unknown software vulnerabilities. Thus, to effectively protect against these attacks, a comprehensive defence strategy must be implemented. This strategy should include not only preventative technologies but also a well-planned response plan in the event of an attack.

With that in mind, the open-appsec initiative is an innovative open-source solution that leverages machine learning for comprehensive web applications and API security for modern business needs. Unlike traditional web application firewalls (WAFs), open-appsec offers a unique approach to preventing zero-day exploits by utilising a machine learning-based security model. In particular, the system performs contextual analysis to learn the regular behaviour of users on the web application, allowing it to identify requests that deviate from normal operations automatically. These requests are then evaluated to determine if they are malicious or not. With open-appsec, organisations can enjoy improved visibility, protection, and manageability for their web applications and APIs.


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