An attacker exploits actual code of an application and uses a security hole to carry out an attack before the application vendor knows about the vulnerability. Which of the following types of attack i

A replay attack involves capturing valid data transmissions and maliciously repeating them later to gain unauthorized access or achieve a fraudulent outcome.

A zero-day attack refers to an exploit for a vulnerability that is unknown to the software vendor or public, meaning there has been "zero days" for the vendor to prepare a fix. Attackers leverage these undiscovered security holes to carry out their attacks before any patches are available.

A Man-in-the-middle (MitM) attack occurs when an attacker intercepts communication between two parties, impersonating each to the other to eavesdrop or alter messages.

A Denial-of-Service (DoS) attack aims to make a machine or network resource unavailable to its intended users by flooding it with traffic or exploiting a vulnerability to crash it.