A “zero-day” refers to a software vulnerability or security flaw that is exploited by cyberattackers before the developer or vendor of the affected software is aware of it (i.e., “zero days” have passed since its discovery). Zero-day vulnerabilities are called as such because the software vendor has “zero days” to fix the problem and release a security patch before it is actively exploited.
Key characteristics of zero-day vulnerabilities:
- Undisclosed: Zero-day vulnerabilities are not publicly disclosed before they are exploited. This means that the software vendor and the general public are unaware of the vulnerability until it’s being used for malicious purposes.
- High Risk: Zero-days pose a significant security risk because they can be used to compromise systems, steal data, or carry out other malicious activities before protective measures can be implemented.
- No Patch Available: Since the vulnerability is not publicly known, there is no patch or security update available to fix the issue. This leaves software users vulnerable to attacks until a patch is developed and distributed.
- Targeted Attacks: Zero-day vulnerabilities are often used in highly targeted attacks, typically against specific individuals, organizations, or systems.
- Valuable Commodities: Zero-day vulnerabilities are valuable on the black market, and they can be bought, sold, or traded by cybercriminals and state-sponsored hacking groups.
- Discovery Methods: Zero-day vulnerabilities are often discovered by security researchers, ethical hackers, or malicious actors through extensive analysis of software code, reverse engineering, or other means.
It’s important to note that software vendors and security researchers actively work to identify and patch vulnerabilities. Once a zero-day vulnerability is discovered and reported to the software vendor, the responsible party typically works to release a security update (patch) to address the issue. However, there is a period of vulnerability between the discovery of the vulnerability and the release of the patch, during which attackers may take advantage of it.
Users and organizations can protect themselves from zero-day vulnerabilities by regularly updating their software, using security software, and following best practices for cybersecurity. Software vendors and security researchers also play a crucial role in identifying and mitigating these vulnerabilities to minimize their impact.