Audit Show All Filename Extensions

LowLevel 1Manual reviewmacos

Description

A filename extension is a suffix added to a base filename that indicates the base filename's file format. This is intended for any user that logs into the GUI and has a home folder and not for service accounts. For the audit, we will continue to verify that every account with a home folder has filename extensions enabled.

How it is checked

Audit method: Manual review

This recommendation cannot be checked automatically. A scan lists it with these instructions when you pass --include-manual.

GUI: Finder > Finder in the menu bar > Settings > Advanced > Verify that Show all filename extensions is set. Terminal: sudo -u <username> /usr/bin/defaults read /Users/<username>/Library/Preferences/.GlobalPreferences.plist AppleShowAllExtensions ; sudo -u firstuser /usr/bin/defaults read /Users/firstuser/Library/Preferences/.GlobalPreferences.plist AppleShowAllExtensions

How it is fixed

Fix method: Guidance or infrastructure patch

Terminal: sudo -u <username> /usr/bin/defaults write /Users/<username>/Library/Preferences/.GlobalPreferences.plist AppleShowAllExtensions -bool true ; sudo killall Finder ; sudo -u seconduser /usr/bin/defaults write /Users/secondname/Library/Preferences/.GlobalPreferences.plist AppleShowAllExtensions -bool true. GUI: Finder > Finder in the menu bar > Settings > Advanced > Set Show all filename extensions to enabled.

Properties

Operating systems: macos-15
Tags: macosapplications
Reference: CIS Apple macOS 15.0 Sequoia Benchmark v2.1.0 - 6.1.1 Audit Show All Filename Extensions