N10-009 domain - 14% of the exam

Network Security

Network Security is 14% of the CompTIA Network+ (N10-009) exam. These are the objectives it covers, each with practice questions and worked explanations.

Objectives in this domain

Sample question from this domain

Free sampleNetwork Securitymedium

A technician captures traffic on a switch mirror port and finds that user login credentials for an internal web application are travelling in readable cleartext over HTTP, so anyone with packet-capture access can read them. Which element of the CIA triad is most directly compromised by this finding?

  • AIntegrity, because an attacker who reads the credentials could later modify the account, so the trustworthiness of the stored data is the main loss.
  • BAvailability, because exposing the login could lead to the account being locked out and the legitimate user then denied access to the application.
  • CConfidentiality, because the credentials can be read by an unauthorised party who captures the packets, defeating the aim of keeping data secret in transit. Correct
  • DNon-repudiation, because cleartext credentials would make it impossible to prove who carried out a given action later on.
Reading data such as credentials in cleartext on the network breaks confidentiality, the assurance that information is disclosed only to authorised parties. Confidentiality is the assurance that data is accessible to authorised parties; credentials sent in cleartext can be read by anyone capturing the traffic, which is a direct confidentiality breach rather than alteration or loss of access.

Why A is wrong: Integrity concerns unauthorised alteration of data; capturing readable credentials exposes them but does not change any stored value, so this is not the principle harmed here.

Why B is wrong: Availability is about authorised users reaching a service; the web application stays reachable and no disruption has occurred, so availability is not what the cleartext exposure breaks.

Why C is correct: Confidentiality is the assurance that data is disclosed to authorised parties alone; cleartext credentials on the wire can be read by anyone capturing packets, which is precisely this loss.

Why D is wrong: Non-repudiation is the inability to deny an action and is not one of the three CIA-triad pillars, so it cannot be the triad element compromised by packet exposure.

Other domains in this exam

See also the N10-009 cert hub, the study guide, and the cheat sheet.

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