Hacking My Own Mac App: Penetration Testing macOS Defense Boundaries in a VM
A Japanese version of this is on Zenn . I build and sell a macOS network-security menu bar app called RoamSwitch . In a previous post , I wrote about attacking my own Mac from an Arch Linux box on the same LAN to see how it handled basic reconnaissance and rogue device probes. Since then, as I kept adding features and refactoring, a nagging question kept resurfacing: Are we introducing…
This article details a penetration testing process for a macOS network-security app called RoamSwitch. The author built a disposable macOS virtual machine inside a disposable macOS virtual machine to thoroughly probe all five defense boundaries from the outside. The five defense boundaries tested are:
1. XPC Authorization Boundary
2. Packet Filter (pf) Ruleset Priority & Air-Gap Containment
3. Port Anomaly Guard & Exposure Detection
4. MCP Server Read-Only Invariant & Parser Fuzzing
5. ARP Gateway Monitor & Integrity
For each defense boundary, the author performed specific tests and recorded the results. For example, when testing the XPC Authorization Boundary, they dynamically compiled an unsigned Swift probe binary lacking Apple Developer Team ID and attempted to call enableAirGap. The privileged helper correctly rejected the unauthorized XPC caller.
The most realistic threat in the testing scenario involved a compromised smart home device on the home network trying to probe and attack the Mac. In this case, when a process exposed port 8080 to the external LAN, RoamSwitch automatically blocked it and shielded external access.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
