Joe a company’s new security specialist is assigned a role to conduct monthly vulnerability scans
across the network. He notices that the scanner is returning a large amount of false positives or
failed audits. Which of the following should Joe recommend to remediate these issues?
A.
Ensure the vulnerability scanner is located in a segmented VLAN that has access to the
company’s servers
B.
Ensure the vulnerability scanner is configured to authenticate with a privileged account
C.
Ensure the vulnerability scanner is attempting to exploit the weaknesses it discovers
D.
Ensure the vulnerability scanner is conducting antivirus scanning
Explanation:
The vulnerability scanner is returning false positives because it is trying to scan servers that it
doesn’t have access to; for example, servers on the Internet.
We need to ensure that the local network servers only are scanned. We can do this by locating the
vulnerability scanner in a segmented VLAN that has access to the company’s servers.
A false positive is an error in some evaluation process in which a condition tested for is mistakenly
found to have been detected.
In spam filters, for example, a false positive is a legitimate message mistakenly marked as UBE —
unsolicited bulk email, as junk email is more formally known. Messages that are determined to be
spam — whether correctly or incorrectly — may be rejected by a server or client-side spam filter
and returned to the sender as bounce e-mail.
One problem with many spam filtering tools is that if they are configured stringently enough to be
effective, there is a fairly high chance of getting false positives. The risk of accidentally blocking an
important message has been enough to deter many companies from implementing any anti-spam
measures at all.
False positives are also common in security systems. A host intrusion prevention system (HIPS),
for example, looks for anomalies, such as deviations in bandwidth, protocols and ports. When
activity varies outside of an acceptable range – for example, a remote application attempting to
open a normally closed port — an intrusion may be in progress. However, an anomaly, such as a
sudden spike in bandwidth use, does not guarantee an actual attack, so this approach amounts to
an educated guess and the chance for false positives can be high.
False positives contrast with false negatives, which are results indicating mistakenly that some
condition tested for is absent.