Which of the following is the best method for quickly identifying systems vulnerable to a newly announced vulnerability?

The best method for quickly identifying systems vulnerable to a newly announced vulnerability is to identify affected versions and check systems using an automated scanner. This approach is efficient because automated scanners can rapidly assess numerous systems against a defined set of criteria, including versions of software and specific configurations known to be associated with the vulnerability.

Automated scanning tools are designed to quickly compare the systems within an organization against a database of known vulnerabilities and can generate reports highlighting which systems are at risk. This allows for timely remediation efforts to be put in place.

In contrast, running manual tests on each server is resource-intensive, time-consuming, and less feasible when there are numerous systems to assess. Checking system logs may provide insights into past events or ongoing issues, but it does not proactively identify vulnerabilities across the environment. Consulting external databases can enhance knowledge and context but does not directly assess the state of systems, making it less effective for an immediate assessment of current vulnerabilities.

Thus, leveraging an automated scanner provides a rapid and comprehensive means to evaluate many systems against newly identified vulnerabilities, making it the most effective choice for this situation.