CompTIA XK0-005 Exam - Topic 4 Question 54 Discussion

Actual exam question for CompTIA's XK0-005 exam

Question #: 54
Topic #: 4

[All XK0-005 Questions]

A developer is unable to access a Linux server via SSH. Given the following output:

SSH server configuration (/etc/ssh/sshd_config):

PermitRootLogin no

PubkeyAuthentication yes

PasswordAuthentication yes

GSSAPIAuthentication yes

X11Forwarding no

User Information (/etc/passwd):

developer:x:1000:1000:comptia:/home/developer:/bin/bash

User Shadow File (/etc/shadow):

developer:!!::0:99999:7:::

Which of the following explains why the developer is unable to log in to the server?

AThe developer's private key has been deleted from the server.

BThe developer's account has been locked out.

CThe developer's public key is in the wrong location.

DSSH has been disabled for user log-in.

Show Suggested Answer

Suggested Answer: B

The reason the developer cannot log in is because their account is locked. This is indicated by the '!!' in the /etc/shadow file:

developer:!!::0:99999:7:::

The '!!' in the password field means the account is locked, and the user cannot authenticate using a password.

To unlock the account, the administrator must reset the password:

passwd developer

OR, if SSH key authentication is used, the administrator can remove the lock without setting a password:

usermod -U developer

Why the other options are incorrect?

A . The developer's private key has been deleted from the server. Incorrect, because the login attempt is failing before key authentication even starts.

C . The developer's public key is in the wrong location. Incorrect, because the SSH configuration (PubkeyAuthentication yes) allows key-based authentication, but the user is still unable to log in. The issue is with the account lock.

D . SSH has been disabled for user log-in. Incorrect, because PasswordAuthentication yes confirms SSH is enabled for users (except root).

CompTIA Linux+ Official Documentation

Linux User Management -- Red Hat

by Sonia at Jun 16, 2025, 11:44 AM

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Antonio

2 months ago

SSH isn't disabled for user log-in, so D is out.

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Joanna

2 months ago

Wait, can you really lock an account like that? Seems harsh!

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Lea

2 months ago

I thought it was A at first, but that shadow file is clear.

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Corazon

3 months ago

The developer's account is locked out. Check the shadow file!

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Venita

3 months ago

Definitely B, that "!!" means the account is inactive.

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Annamaria

3 months ago

I don't think SSH is disabled for the user since "PasswordAuthentication yes" is set, but I'm not completely confident about that.

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Jeniffer

3 months ago

The public key location could be an issue, but I thought that would show a different error message. I'm leaning towards the account being locked.

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Layla

4 months ago

I feel like I've seen a question like this before, and it was about SSH settings. The "PermitRootLogin no" doesn't seem to apply here since the user isn't root.

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Joaquin

4 months ago

I remember something about the user account being locked, and I think the "!!" in the shadow file indicates that, but I'm not entirely sure.

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Mitzie

4 months ago

This is a tricky one, but I'm going to carefully analyze the information provided and try to come up with a solid strategy to identify the root cause. I'm confident I can figure this out.

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Brynn

4 months ago

Ah, I think I've got it! The developer's public key must be in the wrong location. That would explain why they can't log in, even with password authentication enabled.

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Isadora

4 months ago

I'm a bit confused here. The server settings look fine, and the user account is active. I wonder if there's something else going on that's preventing the developer from logging in.

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Lucy

5 months ago

Okay, let's see. The SSH server is set to allow password authentication, so that's not the issue. Maybe the developer's account is locked out?

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Dorian

5 months ago

Hmm, this one seems tricky. I'll need to carefully review the server configuration and user information to figure out what's going on.

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Jess

7 months ago

SSH hasn't been disabled, so it's probably not that. My money's on the account being locked out.

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Orville

7 months ago

B) The developer's account has been locked out.

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Shawnee

7 months ago

A) The developer's private key has been deleted from the server.

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Lorenza

8 months ago

Haha, looks like the developer needs to remember their password! Definitely not a good idea to have a locked account.

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Laurel

7 months ago

C: A) The developer's private key has been deleted from the server.

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Rocco

7 months ago

B: Oh no, that's not good. They should check with the system administrator to unlock their account.

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Skye

7 months ago

A: B) The developer's account has been locked out.

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Lisha

8 months ago

I think the developer's public key is in the wrong location. The SSH configuration allows public key authentication, so the key must not be properly set up.

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Lawrence

7 months ago

D: It's possible that the key is not properly set up for authentication.

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Johnna

7 months ago

C: Maybe the developer needs to check the location of their public key.

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Marylou

8 months ago

B: That makes sense, the SSH configuration allows public key authentication.

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Angella

8 months ago

A: The developer's public key is in the wrong location.

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Laurel

8 months ago

But could it also be that SSH has been disabled for user log-in?

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Teri

8 months ago

I agree with Benton, the shadow file shows '!!' which means the account is locked.

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Benton

8 months ago

I think the developer's account has been locked out.

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Portia

9 months ago

The issue is likely with the developer's account being locked out. The shadow file shows the password field is '!!', which indicates the account is locked.

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Marla

8 months ago

C: Looks like the developer needs to contact the system administrator to unlock the account.

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Dean

8 months ago

B: That makes sense, the shadow file shows the account is locked.

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Ressie

8 months ago

A: The developer's account has been locked out.

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