אילו מהבאים מהווה פגיעות (vulnerability)?

Use of password only and not 2-way verification: While not using 2-factor authentication (2FA) increases risk, it does not necessarily constitute a clear vulnerability. It would be considered a security weakness or bad practice, but not necessarily a vulnerability by itself. This is why it's likely not included in the final answer. Using telnet to configure the system: Vulnerability: Telnet transmits data, including passwords, in plain text, making it susceptible to eavesdropping. It’s a known security risk, especially when configuring systems remotely. More secure alternatives like SSH should be used. Failure to keep activity logs: Vulnerability: Without activity logs, tracking unauthorized access or detecting security breaches becomes difficult. It is a significant vulnerability, as you would have no evidence of suspicious activity or intrusions. Using default passwords on networked devices: Vulnerability: Default passwords are well-known and easily exploitable by attackers. Failure to change default passwords is a classic security vulnerability. Answer 2, 3, 4: This suggests that the most severe vulnerabilities identified are those in answers 2, 3, and 4. All three involve clear, well-established vulnerabilities in system security. Everything: This would imply that all the items listed are vulnerabilities. However, as mentioned earlier, not using 2FA is more of a bad practice than a direct vulnerability, which is likely why this was not the correct answer.