A zero-day vulnerability is a software security flaw that is disclosed to the public but doesn't have a patch in place to fix the flaw. Zero-day attacks have been increasing at an alarming rate over the last few years. Even though zero-day vulnerabilities can't be fixed without patches from the vendor, it is nevertheless necessary to mitigate them before an attacker exploits the vulnerability. Since time is a crucial factor with zero-day vulnerabilities: the sooner you mitigate, the better. Vulnerability Manager Plus helps mitigate zero-day vulnerabilities by deploying scripts that enforce secure configurations, alter registry values, close vulnerable ports.
Note: It should be noted that even after the vendor releases a patch for a zero-day vulnerability, it will be listed under zero-day vulnerabilities because of its severity and importance.