Responding to a Zero-Day Vulnerability Exploited in a High-Profile Attack

A.

The correct answer is A. Reassess the risk in terms of likelihood and impact.

Explanation:

A zero-day vulnerability is a software flaw that is unknown to the vendor and, therefore, has no patch or fix available. As a result, the vulnerability can be exploited by attackers before it is discovered and remediated. In this scenario, the organization had previously accepted the risk associated with the zero-day vulnerability, which means that they had evaluated the risk and determined that the likelihood and impact were acceptable.

However, the recent high-profile attack on another organization in the same industry that exploited the same vulnerability is a significant event that could change the likelihood and impact of the risk. The information security manager should reassess the risk associated with the vulnerability to determine whether the risk has increased in light of the attack.

The reassessment should consider factors such as the severity of the attack on the other organization, the similarity of the attack to the organization's environment, and any other relevant information. The results of the reassessment will help the information security manager to determine whether additional actions are necessary to mitigate the risk.

Developing best and worst-case scenarios (B) and evaluating the cost of remediating the vulnerability (D) may be appropriate steps once the risk has been reassessed. However, these steps should only be taken after the reassessment has been completed.

Reporting the breach of the other organization to senior management (C) may be appropriate if it is relevant to the organization's risk assessment or incident response plan. However, it is not the first course of action that the information security manager should take in response to the attack.