Release Notes

Improvements

• Improved Automatic Profile Switching. The delay between a network change and the resulting profile change has been significantly reduced.
• A warning sign is now shown in the menu bar status icon if the Little Snitch network content filter got deactivated in System Preferences > Network.

Bug Fixes

• Fixed a bug where the pop-up button for selecting the domain did not appear in connection alerts.
• Fixed a bug where an identity mismatch error was incorrectly shown for the operating system kernel.
• Increased startup timeouts to facilitate booting on slow Macs (with HDDs).
• Fixed a bug where (in some cases) an Internet Access Policy was not shown in the connection alert.
• An incorrect ownership of the Launch Daemon and Launch Agent configuration files is now fixed automatically during the installation and update process.
• Fixed a crash when an invalid protocol number was present in a rule.
• Fixed a bug where servers could have a trailing dot in their name.

Known Issues

• On macOS Big Sur 11.0.1 the system may freeze and the computer restart when certain apps are started.
  Has been fixed by Apple in macOS 11.1
  Learn more…
• VPNs of type Cisco IPSec are incompatible with Network Extensions.
  Has been fixed by Apple in macOS 11.1
  Learn more…
• Traffic of some Apple processes is not available to Network Extensions.
  Will be fixed by Apple in macOS 11.2
  Learn more…

Improvements

• New icons in the Suggestions section of the Rules Window.
• Improved selection behavior in the Rules Window after deleting a rule.
• Improved status menu to show the selected profile at the top level of the menu.
• Improved layout of numerical data rate values shown in the status menu icon.
• Improved performance when launching Network Monitor.
• Improved updating the Little Snitch app to a newer version via Drag and Drop. The app will now start automatically to perform the necessary completion of the installation.

Bug Fixes

• Fixed a bug where rules making connections private in Network Monitor would not become effective until a restart.
• Fixed a crash when a connection alert should be shown for www.domain where domain is a top level domain.
• Fixed incorrect display of port number for incoming connections. Previous versions showed the remote port instead of the local port.
• Fixed a possible random crash of the Network Extension.
• Deny-rules are now always applied, regardless of the trustability of the process.

Improvements

• If the identity of a process is not checked, the identity of helper processes is now also not checked. This is a concession to the fact that apps without code signature usually ship with helpers that have no code signature. In addition, it allows iOS developers to disable identity checks on Xcode, thereby disabling identity checks on simulator apps running in Xcode's debugger.

Bug Fixes

• Fixed a bug where configuration changes such as modified preference settings could get lost after a restart of the computer.
• Fixed a bug where access to URLs like https://1.2.3.4/ would be interpreted as host 1.2 in domain 3.4.
• Improved compression of disk image to reduce the size of the download.
• Added missing localization in Connection Alert.
• Fixed a bug where Network Monitor opened unexpectedly when the demo period ended.

Improvements and new features

• Improved handling of DNS lookups. It’s no longer necessary to allow DNS lookups for each process individually.
• Extended debug capabilities of the command line tool.

Bug fixes

• Addressing an issue that could cause Little Snitch helper processes to prevent from getting started.
• Fixed a crash when loading a corrupted configuration file.

What’s new in Little Snitch 5?

There has been quite a bit of public discussion recently about the deprecation of various types of kernel extension on macOS. Among them are Network Kernel Extensions (NKEs). You probably did not care so far, but Little Snitch 4 was based on an NKE to do its job. Since NKEs are now deprecated and no longer officially supported by Apple, we have spent the last year rewriting the core of Little Snitch to the Network Extension (NE) framework. While working on this core, we took the chance to revise some old design decisions and add some long anticipated features.

So what are the benefits of the new version?

• Compatibile with (and requires) macOS Big Sur.
• Future-proof, because it is based on the new Network Extension and Endpoint Security frameworks.
• Drag and Drop installation and upgrade, no reboot required.
• Universal Binary which runs on both Intel and Apple Silicon Macs.
• Little Snitch now comes with a command line interface for preferences editing, configuration import and export, debugging, logging and access to traffic history.
• The time range available in Network Monitor’s traffic diagram has been extended from one hour to up to a year.
• Rules can now specify a list of port numbers, not just one contiguous range as before.
• The export format for backups is human readable normalized JSON.
• Recording of network statistics is done independently of Network Monitor. You can quit Network Monitor and still have statistics recorded.
• Live traffic logs via command line tool.
• Ready for mass deployment installation in corporate environments.

Improvements and new features

• Optionally control access to /dev/bpf devices (Berkeley Packet Filter). These devices can be used to send and receive data with arbitrary network protocols. Requires installation of an Endpoint Security module in Little Snitch > Preferences > Advanced.

Bug Fixes

• Improved recovery when reading broken configuration files.
• Fixed a memory leak in the Little Snitch Network Extension.
• Numerous other bug fixes.

Improvements and new features

• Lots of user interface refinements to match the new look of macOS Big Sur.
• Rules can now be created for a list of port ranges, not just a single range.
• Added command line interface for accessing connection history and traffic log data.
• The traffic diagram in Network monitor can now display traffic data from up to one year (compared to the previous 1 hour).
• The menu for selecting the time period that’s displayed by Network Monitor has been moved from the Filter menu in the search field to View menu in the menu bar.
• Various performance improvements.

Bug Fixes

• Fixed a bug where a connection alert would not go away after clicking allow or deny.
• Fixed various crashes of Network Monitor.
• Fixed a bug where Little Snitch complained about a code modification although the process was not modified.
• Reduced the number of cases where connection alerts for Internet addresses instead of server names were shown.
• Lots of other minor bug fixes.

• Improved notification handling. All notifications are now generated by one single component (the “Little Snitch Agent”), which reduces the number of alerts shown by macOS for allowing the display of these notifications.
• Code identity checks now provide information about a developer’s name, and not just the developer’s team identifier.
• Improved information shown when the code signature of a process became invalid because a library with missing code signature was loaded.
• Improved debug logging. Little Snitch no longer writes log messages to individual log files but uses the logging facilities of macOS.
• Added a command line API for accessing log messages related to Little Snitch.
• Removed menu items responsible for Network Monitor snapshots because snapshots are no longer available.
• Fixed possible crashes when importing backups.
• Various bug fixes and improvements.

• This release brings back “Automatic Profile Switching”. Profiles can now be automatically activated when a network is joined.
• Little Snitch is now scriptable. The app package contains a command line utility at Contents/Components/littlesnitch which can be used to control Little Snitch from scripts or via Terminal. Scriptability must be enabled in Little Snitch’s Security Preferences.
• Improved detection of a remote computer’s domain name for connection alerts and for display in Network Monitor.
• The debug interface for activation and deactivation of components is now password protected.
• Various bug fixes and improvements.

This is a hotfix for a bug in macOS Big Sur Beta 5! Please install this version before upgrading to Beta 5! Otherwise you won’t be able to boot your computer!

This version does not install an Endpoint Security System Extension because Big Sur Beta 5 suffers a kernel panic immediately after booting this System Extension is installed. During upgrade, an existing Endpoint Security System Extension is removed. Currently, the only function of the Endpoint Security System Extension is to detect access to Berkeley Packet Filter devices. This version can therefore not warn when a process tries to access the Berkeley Packet Filter.

The good news is that Big Sur Beta 5 fixes an other kernel panic which occurred on some computers when Little Snitch’s Network Extension was installed.

• Re-implemented process identity checks.
• Re-implemented creation of Diagnostics Reports.
• Various improvements and bug fixes in the user interface.

• This version is now a Universal Binary which runs on both Intel and Apple Silicon Macs.
• Import of rules and settings from previous versions. Choose Little Snitch > File > Restore from Backup… and select a previously created backup file or /Library/Application Support/Objective Development/Little Snitch/configuration4.xpl to import rules and settings from Little Snitch 4. This also works with configurations and backups from Little Snitch 3.
• Export of rules and settings in JSON format. Choose Little Snitch > File > Create Backup…
• Various improvements and bug fixes in the user interface.

• Improved upgrade procedure to work around an issue where macOS sometimes fails to start the newly installed network extension. If this problem occurs, the installer now completely uninstalls the previously installed extension before retrying to install the new one.
• If a previous, incompatible version of Little Snitch is found, this version is now uninstalled automatically in the course of installing the new version. This uninstallation may require a restart of the computer in order to let macOS complete the removal of the kernel extension.
• Several user interface refinements in the rules window.
• Little Snitch now correctly identifies connections that were established by a Java process or a shell script.

This version is primarily a test of the automatic software update. Please install this version using the automatic software update mechanism, not manually.

Installation

If you install this Technology Preview for the first time, please read the installation hints in the release notes of build 6104 below.

Changes

• Redesigned Rules window title bar.
• Little Snitch specific log files are now created in a dedicated Library/Logs/Little Snitch subdirectory.

This Technology Preview of Little Snitch is not yet feature complete. There are several known limitations you should be aware of before you install:

Installation

During the installation you will be asked to enable system extensions in System Preferences > Security & Privacy. After clicking on “Open Security Preferences”, the same dialog will appear once again. This is a bug in macOS Big Sur.

After clicking on “Allow…” in System Preferences > Security & Privacy, you will see a confirmation dialog containing two entries labeled “Placeholder Developer”. These incorrect labels are a bug in macOS Big Sur. The checkboxes for both of these entries must be checked.

Known Limitations

• Rules and settings from previous versions of Little Snitch are not yet imported. Little Snitch will therefore start with the default factory rule set.
• Backup and restore of rules and settings is not yet implemented.
• Code identity checks (usually based on code signature) are not yet implemented.
• Automatic Profile Switching is not yet implemented.
• Some UI components don’t yet have their final appearance and layout.

Tips and Tricks

• All data files are encrypted with a password which is stored in the System Keychain (“Little Snitch Encryption Key”). When you make a backup of the files in /Library/Application Support/Objective Development/Little Snitch/, make sure you also backup this password.
• Traffic history is now recorded by a background process, even when Network Monitor is not running.

Feedback

If Little Snitch crashes or behaves in an unexpected way, please contact our support using the “Send Feedback” button above.

Make sure to include the following information:

• Version number of your Little Snitch app.
• A textual description of the issue: What did you do, what would you have expected to happen and what did happen.
• Crash logs of Little Snitch components, which can be found in Console.app sidebar under “Crash Reports”.
• Logs from Little Snitch under /Library/Logs/ and ~/Library/Logs/.
• Screen shots which describe the issue (if applicable).