What is a Zero Day Exploit?

Posted on by Thomas Janson | Updated:
Reading Time: 3 minutes

Zero Day Vulnerabilities

The zero day vulnerability is a type of hardware or software flaw for which no patch or mitigation is available. The original creators of the product are unaware of a vulnerability, so they will have known about the issue for zero days when one such vulnerability is exploited and brought to their attention.

Malicious actors (a person or entity) attempt to exploit those vulnerabilities in operating systems and software to gain access. For vendors of computer systems and software, zero day vulnerabilities are one of the most dangerous cybersecurity threats.

Zero day exploits can target both big and small businesses, institutions, governments, and in the end, individual users who might be using exploited software. What makes such exploits problematic is that the attackers (an individual or a group) are the only entity aware of the vulnerability, which gives them a significant advantage over people who are supposed to patch it. Using this exploit, attackers can target operating systems, specific software/applications, or entire computer and server networks.

Zero Day Vulnerability Hackers

Significant monetary gain is a driving force for hackers to discover zero day vulnerabilities, but they are also motivated by obtaining protected information and taking control of other people’s systems just because they can. We can divide hackers into three groups.

White Hats

Known as ethical hackers, this group of people is known for their benign intentions. They can either be outsourced individuals or employees of an organization who perform penetration cybersecurity analysis and penetration testing to ensure maximum security of a system or software.

Overall, they use identical hacking techniques as other groups but have the approval of product owners for the sake of improving the security of the software and pre-emptive mitigation of zero day vulnerabilities.

Black Hats

As opposed to white hats, black hat hackers use hacking techniques to illegally find and exploit a zero day vulnerability for the sake of personal gain or malice.

Examples of this activity are stealing and selling personal information like credit card numbers, performing ransomware, and cyber espionage. Black hat hackers can attack a company’s websites and software, destroying critical data.

Grey Hats

Grey hat hackers are a blend of ethical and criminal hacking. Grey hats sometimes illegally break into systems without the approval of the vendor to look for vulnerabilities. They then turn around and report the findings to the owner, but usually for a fee. Due to the nature of a grey hat hacker, they can post their exploits on the Internet if the vendor refuses to pay the extortion fee for finding a vulnerability.

While grey hats do not have the malicious intentions of the black hat hacker, they will still break the law if they deem it necessary.

Vulnerability Discovery Process

In the world of software exploits, the window of vulnerability is the time between vulnerability discovery and mitigation. Even though zero day exploits can differ in their type, we can still determine several key steps in the vulnerability timeline:

  • Hackers discover the vulnerability and perform a zero day exploit.
  • Software creators become aware of the exploit and release a security vulnerability patch.
  • The majority of users update and apply the patch to fix their impacted systems.

The exact number of days or years an exploit is active can differ and depends on many factors like:

  • The complexity of the vulnerability/exploit/patch.
  • The type of software used.
  • The number of impacted users.

As hackers do not publicize the existence of a vulnerability or exploit, it is difficult to measure the exact length of time one is present. Microsoft Window’s Internet Explorer vulnerability affected some versions of the released software in 2001. As Microsoft only confirmed this vulnerability in 2008, the exploit could have lasted up to 7 years.

Protect Against Zero Day Exploits

Even though it is challenging to ensure protection against zero day exploits (due to their nature), preventative measures can minimize the impact of an existing vulnerability:


Zero day vulnerabilities can be found at a moment’s notice, often by those with ill intentions. Malware development and hacker interest advance at the same rate as technology, so taking preventative steps to minimize vulnerabilities is the best way to combat potential threats and exploits.

Liquid Web offers various products to enhance the security and protection of your server. Reach out today to see how Liquid Web can help secure our website!

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About the Author: Thomas Janson

Thomas Janson joined Liquid Web's Operations team in 2019. When he is not behind the keyboard, he enjoys reading books, financial statements, playing tennis, and spending time outdoors.

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