The term “zero-day” refers to the period between the discovery of a software defect and the availability of a fix. Since the security companies are unaware of it, no patch is available. A zero-day vulnerability is a previously undisclosed computer software flaw that attacks silently before security teams are aware of it. Many of the vulnerabilities that fall under the category of application security can be classified as zero-day vulnerabilities, since they are generally unique to a particular application, they will never be listed in a common vulnerability database.












