The attacker sent data that was able to manipulate the return address that is reserved to store expected data

Complete Question:

An attacker gained remote access to a user's computer by exploiting a vulnerability in a piece of software on the device. The attacker sent data that was able to manipulate the return address that is reserved to store expected data. Which vulnerability exploit resulted from the attacker's actions?

A buffer overflow.

Explanation:

In Computer science, a buffer can be defined as a temporary area set aside for data storage. Buffers reside in the random access memory (RAM).

In the event that, a system process or program places more data (much more than what was originally or initially intended to be allocated for data storage) in a buffer, the extra data overflows. Consequently, this would result in having some of the data to flow into other buffers and thus, causing the data to be overwritten or corruption of the data being held in that buffer.

For example, we can liken a buffer-overflow to pouring water (data) into a container (program memory), once it is filled the water begins to overflow as the container has reached its maximum amount.

In this scenario, the vulnerability exploit which resulted from the attacker's actions by manipulating the return address that is reserved to store an expected amount of data is referred to as a buffer overflow.