Which type of security problems can a voice mail service be vulnerable to?

A voice mail service can indeed be vulnerable to curiosity, malice, and toll fraud. Curiosity refers to unauthorized users trying to access voice mail to listen to messages out of sheer interest, which can lead to privacy breaches. Malice may involve more intentional actions, where individuals exploit vulnerabilities within the system to damage content or disrupt service. Toll fraud is a specific type of malicious activity where hackers gain unauthorized access to voice mail systems to make fraudulent long-distance calls, which can impose significant financial costs on organizations. These factors highlight the need for robust security measures to protect voice mail systems from various threats.

While the other options reflect different types of vulnerabilities or issues, they do not align as closely with the specific risks associated with voice mail services as the correct answer does.