Zero-Day Threat


A Zero-Day Threat refers to a vulnerability in software or hardware that is unknown to the parties responsible for patching or fixing the issue. The term “zero-day” denotes that developers have “zero days” to rectify the problem before it can potentially be exploited by hackers. It is particularly dangerous as it means the vulnerability may be exploited before the developer is even aware of its existence.


“Zero-Day Threat” in phonetics is: /ˈziːrəʊ-deɪ θrɛt/

Key Takeaways

<ol><li>A Zero-Day Threat refers to a software vulnerability that has been discovered and exploited by hackers before developers have had the chance to create and implement a solution or patch. This leaves systems highly vulnerable to attacks due to the lack of defense against the threat.</li><li>These types of threats can cause serious damage as they can lead to unauthorized access, data breaches, or widespread system damage before they can effectively be stopped. Businesses, government institutions, and individuals can all be potential targets of these threats.</li><li>The best defense against Zero-Day Threats includes a combination of keeping all software and systems up-to-date, using reliable security software solutions, network monitoring, and maintaining good cyber hygiene, such as not clicking on suspicious links or downloading unknown software.</li></ol>


A Zero-Day Threat is significant in the field of technology and cybersecurity because it represents a software vulnerability that has been discovered but not yet patched or addressed by the software developers. This leaves a potential pathway for hackers or malicious software to exploit the system, often before the developers even become aware of the problem. It is called a ‘Zero-Day’ threat because the developers have zero days to fix the issue before it can potentially be exploited. It underscores the constant race between cybersecurity experts and malicious actors, and highlights the importance of regular system updates and patches to maintain the security of systems and data.


A zero-day threat is essentially a previously unknown vulnerability in a system or software that malicious hackers can exploit to gain unauthorized access, gain control, or disrupt the system’s functions. The term “zero-day” pertains to the fact that developers have “zero days” to fix the issue since they were unaware of the threat until it was actually exploited. Such threats are purposefully used by cybercriminals to take advantage of the vulnerability before it can be rectified, hence creating a significant challenge in the sphere of cybersecurity.The purpose of a zero-day threat from the perspective of a hacker is to exploit the weakness for various illicit purposes. This may include stealing sensitive data, holding systems to ransom, or simply causing chaos and disruption. Given that the bug or vulnerability is unknown to developers and security teams at the time of the attack, it provides hackers a temporary advantage, allowing them to bypass security controls and infiltrate the network or system. As such, identification and mitigation of zero-day threats have become a critical aspect of cybersecurity practices.


1. Stuxnet: This malicious computer worm was discovered in 2010 and is believed to be a cyberweapon created by the U.S and Israel. This zero-day threat was targeted at Iran’s nuclear facilities and caused significant physical damage to Iran’s nuclear enrichment program. The worm exploited previously unknown vulnerabilities in Microsoft Windows and Siemens’ industrial software to infiltrate and disrupt Iran’s nuclear program.2. CVE-2018-4878: A zero-day vulnerability identified within Adobe Flash Player in 2018, this threat was used by the suspected North Korean hacking group known as APT37 in a targeted spear-phishing campaign. The flaw in Adobe Flash Player allowed remote code execution, enabling attackers to take control of an affected system. Adobe released a patch promptly after its discovery.3. SolarWinds Orion Software supply chain attack: Discovered in 2020, this zero-day breach affected several high-profile organizations, including U.S. government agencies. The threat actors managed to infiltrate the network management system provided by SolarWinds, embedding malicious code in the software updates. This clandestine breach remained undetected for months and exemplifies the destructive potential of zero-day threats.

Frequently Asked Questions(FAQ)

**Q: What is a Zero-Day Threat?**A: A Zero-Day Threat is a vulnerability in a software, hardware, or firmware that is unknown to the parties responsible for fixing it, such as the vendor. As a result, it presents an open window for hackers to exploit before the vulnerability is noticed and a fix or patch is released.**Q: How does a Zero-Day Threat differ from other threats?**A: Unlike other threats where patches are often available, the challenge with Zero-Day Threats is that they remain unknown until the attack is initiated. Due to this, there is no chance for a prevention strategy or any specific security measure to be put in place before the attack occurs.**Q: What are the potential dangers of a Zero-Day Threat?**A: Zero-Day Threats can potentially cause extensive damage including data breaches, theft of sensitive information and disruption in services. As they exploit vulnerabilities that are not known, the damage can occur rapidly and undetected until it’s too late.**Q: How can we protect against Zero-Day Threats?**A: While it’s impossible to fully prevent a Zero-Day Threat due to their nature, steps can be taken to minimize the chances of an attack or lessen its impact. These include regular software updates, using a robust antivirus software, employing network segmentation and privileging least-privilege policies.**Q: Is it necessary to update software regularly to prevent Zero-Day Threats?**A: Yes, regular software updates are crucial as they often include patches for known vulnerabilities that could potentially become a Zero-Day Threat. Keeping your software, firmware, and hardware up-to-date ensures that you have the most recent security enhancements.**Q: How do I know if I’ve been a victim of a Zero-Day attack?**A: Due to the unpredictable nature of Zero-Day Threats, it can be challenging to identify them. However, unusual system behavior, unexpected data usage or unaccounted network traffic can be signs of a potential Zero-Day attack. Employing a robust security solution that incorporates Zero-Day attack detection can help in this aspect. **Q: How do cybercriminals discover Zero-Day Threats?**A: Cybercriminals often discover Zero-Day Threats through multiple means, including intensive software testing, reverse engineering of patches and updates, and through underground forums or markets where such information is sold.

Related Tech Terms

  • Vulnerability
  • Exploit
  • Patch
  • Firewall
  • Malware

Sources for More Information


About The Authors

The DevX Technology Glossary is reviewed by technology experts and writers from our community. Terms and definitions continue to go under updates to stay relevant and up-to-date. These experts help us maintain the almost 10,000+ technology terms on DevX. Our reviewers have a strong technical background in software development, engineering, and startup businesses. They are experts with real-world experience working in the tech industry and academia.

See our full expert review panel.


About Our Editorial Process

At DevX, we’re dedicated to tech entrepreneurship. Our team closely follows industry shifts, new products, AI breakthroughs, technology trends, and funding announcements. Articles undergo thorough editing to ensure accuracy and clarity, reflecting DevX’s style and supporting entrepreneurs in the tech sphere.

See our full editorial policy.

Technology Glossary

Table of Contents

More Terms