Zero-day Exploit Law and Legal Definition

A zero-day exploit is one that takes advantage of security vulnerability on the same day that the vulnerability becomes generally or publicly known. Zero-day-exploits are usually posted by well-known hacker groups. There are zero days between the time the vulnerability is discovered and the first attack. Software companies shall issue a security bulletin or advisory at the time when exploit becomes known, but companies will not be able to fix the vulnerability. Even if potential attackers hear about the vulnerability, it may take them some time to exploit it; meanwhile, the fix will hopefully become available first.