Challenge ·Medium

Shell History: Delete Sensitive Commands and Prevent Future Logging

Mister P
by  Mister P · on
Linux
Practice managing Bash history by removing a specific sensitive command from history and configuring the shell to prevent space-prefixed commands from being saved.
#bash#shell-history#histcontrol#rhcsa

A junior sysadmin accidentally ran a command containing a secret API key, and the shell history now contains the string supersecret-api-key=abc123XYZ. You need to clean it up and make sure space-prefixed commands won't be logged in future sessions.

Complete the following tasks on rocky-01 as the laborant user:

  1. Remove the command containing supersecret-api-key=abc123XYZ from ~/.bash_history (leave all other history entries intact).
  2. Configure the shell so that commands prefixed with a space are not saved to history, and make this setting persistent across new login sessions.
Hint 1 — Finding the entry

Use history to display the numbered list of commands. Look for the line containing the secret string. Note its number.

Hint 2 — Removing a single history entry

history -d <number> removes a single entry by its line number. After deleting, write the updated history to disk.

Hint 3 — Writing history to disk

In-memory changes to history are not saved automatically. Use history -w to flush the current in-memory history to ~/.bash_history.

Hint 4 — Preventing space-prefixed commands from being logged

Set HISTCONTROL=ignoreboth (or ignorespace) in ~/.bashrc and source the file so the setting is active immediately. The ignorespace value tells Bash to skip saving any command that begins with a space character.

How to Author Challenges on iximiuz Labs

Instead of providing a subpar online editing experience, iximiuz Labs offers a helper CLI tool called labctl, allowing you to use your favorite text editor (or a full-featured IDE) to write content from the comfort of your local machine.

Install labctl CLI

curl -sf https://labs.iximiuz.com/cli/install.sh | sh

This will download and install the latest version of the labctl CLI. You only need to do this once per workstation.

Authorize labctl

labctl auth login

This will open a browser window asking you to authorize labctl to access your account. You need to do it after a fresh install of labctl and repeat it whenever the auth session expires.

Pull challenge content

labctl content pull challenge rhcsa-x200101-challenge-4-c1d04a31

This will create a local copy of the challenge content in a directory named rhcsa-x200101-challenge-4-c1d04a31. You only need to do this once per challenge.

Stream your changes

labctl content push -fw challenge rhcsa-x200101-challenge-4-c1d04a31

Run this command in a separate terminal to continuously upload your changes to the server while editing the challenge in your favorite text editor or IDE.

You can also use labctl to create, list, and delete your content. Learn more about the available commands: labctl content --help

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