What is a Zero Day Vulnerability?
Zero Day as a term is used to define vulnerabilities that have been found to be exploited in the Wild, when it was discovered by “friendly” and informed to the vendor of the affected software or program or in some cases to the general public. “Friendly” has been used here as exploited in the wild implies that the vulnerability has been used for active attacks and since it has been used by someone, it must be known to that someone.
Zero Day, also written as 0-day, is always a concern for the vendors, and rightfully so, as it highlights a risky interval between the release of the vulnerability and the release of the patch, during which the exposure to the clients and users is heightened as not only the initial attacker(the one using the Zero Day before the release), but also newer adversaries will have access to the Vulnerability in the system.
The next step after the release of the patch, would be the rollout of the patch. The duration between the release of the vulnerability and the rollout of the patch is also a time of nervousness for the organizations using the affected component. The organization would first have to wait for the release of the patch and then would have to package and rollout the patch to the multiple assets of the organization. If the first half till the release of the patch makes the vendor nervous, then the second part till the roll out of the patch makes the clients jumpy.
It is highly recommended to patch a Zero Day as soon as possible.
Zero Day attacks are attacks that utilize Zero Day vulnerabilities to carry out an attack on a target. What makes Zero Day Attack so frightening is that the attack has been carried out to exploit a vulnerability that was not known earlier.