MailSafi Glossary of Terms

Zero-day Attack

Also referred to as 0-day attack or Day Zero exploit is an attack that exploits a potentially serious software security weakness that the vendor or developer may be unaware of. Developers or vendors must therefore quickly resolve the vulnerability (zero day) as soon as it is discovered to minimize threats to the software users. To do this, they often need to create a software patch. Until mitigated, hackers can exploit it to cause damage to computer programs, data or networks.

A zero-day attack is so called because it refers to the number of days the software developer has known about the problem.