Final answer:
A CVSS base score of 100 indicates a vulnerability that is very severe and easy to exploit, requiring a 'Very High' level of difficulty.
Step-by-step explanation:
The CVSS (Common Vulnerability Scoring System) is used to assess the severity and difficulty of exploiting a vulnerability.
A CVSS base score of 100 indicates that the vulnerability is very severe and trivial to exploit. In this case, the difficulty level required to exploit this vulnerability would be Very High.
Exploiting this vulnerability would require little to no expertise or specialized knowledge, making it easily accessible to attackers.