Exam objective
CEHEnumeration
This objective sits in Reconnaissance Techniques, which carries 17% of the CEH exam. The questions below are original, written from the official objective title above, and each explanation cites the EC-Council page it rests on.
Objective title verbatim from the official objectives. EC-Council exam page ↗
A worked example
Shown solved, with the whole explanation open: this is what every question here carries.
A mail administrator reviews which SMTP commands a public relay answers. Which pair returns user and mailing list membership information?
Correct.
Checked against rfc-editor.org, September 2026Concept
A protocol built for debugging delivery carries commands whose only purpose is to answer questions about who exists, and those answers are as useful to an outsider as to the postmaster.
Why D
One command verifies whether a named user exists and returns the mailbox, and the other expands a mailing list into the mailboxes on it. Both were written for diagnosing delivery problems.
Source
IETF, RFC 5321: Simple Mail Transfer Protocol, checked September 2026SMTP provides commands to verify a user name or obtain the content of a mailing list. This is done with the VRFY and EXPN commands, which have character string arguments. Implementations SHOULD support VRFY and EXPN (however, see Section 3.5.2 and Section 7.3).
Now you: practice questions
No account needed. The explanation opens when you answer.
Sample question 1 of 3
An administrator disables address verification on the company SMTP servers. Which reply code must the server return so a client cannot read it as a verdict?
Sample question 2 of 3
A team disables the address verification commands on its mail servers and closes the finding. Which residual exposure should the assessor still record?
Sample question 3 of 3
An analyst reviews a directory server log showing a bind with an empty name and an empty password, followed by a subtree search. Which state did that bind create?
That’s 3 of the full CEH bank.
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Continue practicingRead the sources
These are the official pages the questions above cite. Reading them is studying the objective from the primary source, which is what the explanations point you toward anyway.