What is a Zero Day Exploit?

Zero day exploits target vulnerabilities that a software manufacturer has not yet patched. By taking advantage of largely unknown vulnerabilities, these exploits have a high probability of success and are difficult or impossible to protect against using legacy cybersecurity tools.

Stop Zero Day EBook

Zero Day Vulnerabilities and Exploits

Vulnerabilities in software can be discovered in a few different ways. In some cases, the vulnerability is discovered internally by the software manufacturer or ethically reported to them by an external security researcher. In others, the vulnerability is discovered and exploited by cybercriminals.


Most zero day exploits fall into this second category. In this case, there is a window between the vulnerability first being publicly exploited and targeted defenses – in the form of malware signatures or a software update – being released. This is referred to as “day zero” and is where zero day vulnerabilities and exploits get their names.

Examples of Zero Day Exploits

One example of some zero day vulnerabilities is a set of vulnerabilities in Microsoft Exchange servers. While Microsoft initially discovered these vulnerabilities, slow patch cycles meant that many Exchange servers were still vulnerable when cybercriminals started exploiting these vulnerabilities.


Hafnium is an example of a malware that takes advantage of these Exchange vulnerabilities. It exploits these vulnerabilities to gain access to a vulnerable Exchange server and elevate its privileges on the system. This malware is designed to perform information gathering, trying to steal user credentials and emails from exploited systems.

Security Challenges of Zero Day Exploits

Zero day vulnerabilities and exploits are a significant concern for cybersecurity personnel because they are difficult to defend against. Some of the security challenges of zero day exploits include:


  • Lack of Signatures: Many cybersecurity solutions, like some intrusion prevention systems (IPS), rely on signatures to identify and block malware and other attacks. With a zero day exploit, cybersecurity researchers have not yet had the opportunity to develop and release a signature for the exploit, meaning that these solutions are blind to it.
  • Slow Patch Development: With a zero day exploit, the patch development process begins when the vulnerability becomes public (i.e. when attacks exploiting it are detected in the wild). After the vulnerability becomes public, the software manufacturer needs to understand the vulnerability and develop, test, and release a patch before it can be applied to vulnerable systems. During this process, any unprotected devices are vulnerable to exploitation using the vulnerability.
  • Slow Patch Deployment: Even after a patch has been created, it takes time for companies to apply it to their vulnerable software. This is why the Hafnium malware is able to still infect devices even after a patch was made available by Microsoft.


For these reasons, a reactive approach to cybersecurity based on signatures and patching is not effective for zero day vulnerabilities and exploits. Organizations must proactively prevent attacks to block these novel exploits.

How to Protect Against Zero Day Exploits

For zero day exploits, the main problem that organizations face is a lack of information. If a security team has information about a particular threat, then security solutions can be configured to block that threat. However, gaining access to this information and disseminating it through an organization’s security architecture is a major challenge for many organizations.


Effective zero day protection requires a security architecture with the following features:


  • Consolidation: Many organizations rely upon a disaggregated collection of point security solutions, which are difficult to operate and maintain. Security consolidation ensures that, once a zero day threat is discovered, an organization’s entire security architecture can identify and respond to it in a coordinated fashion.
  • Threat Prevention Engines: Threat prevention engines are specialized detection solutions that are designed to identify common malware features and attack techniques. For example, a threat prevention engine may perform CPU inspection to detect return-oriented programming (ROP) or look for code reused from known malware.
  • Threat Intelligence: Information is crucial to the fight against zero day exploits. Access to a source of high-quality threat intelligence enables an organization to learn from others’ experience and find out about zero day threats before they are targeted.


Check Point’s prevention-first approach is the only way to effectively protect against unknown threats like zero day exploits. ThreatCloud is the world’s largest cyberthreat intelligence database and processes an average of 86 billion transactions per day. This allows it to identify approximately 7,000 previously unknown threats each day, enabling organizations to detect and block these zero day exploits against their systems.


ThreatCloud leverages artificial intelligence (AI) to process data and detect threats. To learn more about the importance of AI for zero day exploit detection, check out this whitepaper. You’re also welcome to  sign up for a demo to see how Check Point’s advanced endpoint protection solutions can protect your organization’s remote workforce against zero day threats.

This website uses cookies for its functionality and for analytics and marketing purposes. By continuing to use this website, you agree to the use of cookies. For more information, please read our Cookies Notice.