OpenSnitch is a GNU/Linux port of the Little Snitch application firewall (github.com)

Article summary

OpenSnitch is a GNU/Linux interactive application firewall inspired by Little Snitch, which monitors and restricts outbound connections that applications are trying to make. It provides features such as interactive outbound connections filtering, blocking ads and trackers, and configuring system firewall from the GUI. OpenSnitch is designed to give users insight into changed app behaviors and block unwanted connections. The project is open-source and available on GitHub.

Main themes

• Application Firewalls
• Network Security
• Privacy
• Tracking and Surveillance
• Linux and Open-Source Software
• Security Trade-Offs

What commenters say

• Using application firewalls like Little Snitch can reveal unexpected connections and tracking behavior by popular applications.
• Some users find maintaining access lists for application firewalls to be tedious and prone to errors.
• Application firewalls may not be effective against all types of tracking and data exfiltration, such as DNS-based attacks.
• The use of non-standard ports for public internet-facing services can be a security measure to reduce script-based attacks.
• State-level actors may be able to bypass application firewalls using advanced techniques, but these firewalls are still useful for detecting changed app behaviors.
• Setting up and configuring application firewalls can be overwhelming, especially on machines with many installed software applications.
• There is a trade-off between the benefits of using application firewalls for privacy and the potential security risks of running software with bugs and vulnerabilities.
• Some users prefer to use alternative solutions, such as pi-hole or NextDNS, for blocking ads and tracking domains.