What is a zero-day exploit?

What is a zero-day exploit?

• A. An attack that occurs on the same day a vulnerability is discovered
• B. A known exploit that has been patched
• C. Any attack on outdated software
• D. An exploit that affects zero users

Answer: (A)

A zero-day exploit refers to an attack that occurs on the same day a vulnerability in software is discovered, before the developer has had a chance to patch the issue. This term comes from the idea that there are "zero days" of protection against the vulnerability because it is newly found and has not yet been addressed by a patch or update. These exploits can be particularly dangerous, as they allow attackers to take advantage of the unpatched vulnerability immediately, potentially leading to significant damage before the software developer can remediate the issue. In contrast, exploits that are known and have been patched are no longer considered zero-day exploits, as the vulnerability is no longer unknown to the developers or the public, and mitigations exist to protect against it. Similarly, attacks on outdated software can involve known vulnerabilities that have been previously documented and patched, which does not classify them as zero-day exploits. Lastly, the notion of an exploit affecting zero users does not accurately capture the essence of zero-day vulnerabilities, as the term is concerned with the timing of the exploit relative to the discovery of the vulnerability rather than the number of affected users.

A zero-day exploit refers to an attack that occurs on the same day a vulnerability in software is discovered, before the developer has had a chance to patch the issue. This term comes from the idea that there are "zero days" of protection against the vulnerability because it is newly found and has not yet been addressed by a patch or update. These exploits can be particularly dangerous, as they allow attackers to take advantage of the unpatched vulnerability immediately, potentially leading to significant damage before the software developer can remediate the issue.

In contrast, exploits that are known and have been patched are no longer considered zero-day exploits, as the vulnerability is no longer unknown to the developers or the public, and mitigations exist to protect against it. Similarly, attacks on outdated software can involve known vulnerabilities that have been previously documented and patched, which does not classify them as zero-day exploits. Lastly, the notion of an exploit affecting zero users does not accurately capture the essence of zero-day vulnerabilities, as the term is concerned with the timing of the exploit relative to the discovery of the vulnerability rather than the number of affected users.