Flutter based Mac OSX Thick Client SSL Pinning Bypass

Sanjay encountered a scenario where the application was built on top of a Flutter framework and had an SSL pinning check in one of the embedded libraries. Due to this check, the application provided an SSL pinning error when it was configured using Burp.
To share our experience and for the purpose of this blog, we will be using ‘thickclient.example.com’ as a backend URL for OSX thick client application.

TL;DR

Bypass SSL Pinning implementation for Flutter based Mac OSX thick client application by hooking script in Mac OSX thick client application.

Problem Statement

The challenge was to or modify the network traffic generated by Mac OSX thick client application in Burp Proxy, as the application provided an SSL pinning error when configured using Burp.

Problem

During the process of Mac OSX thick client application pentest, to capture the application’s HTTP traffic, we used well-known like Burp Suite, Charles Proxy, and Proxyman, configured using well-known proxy configuration techniques. It was observed that none of the tools and techniques could capture the Mac OSX thick client application’s traffic.

Using Wireshark to analyze the thick client application network traffic, we

Read More: https://notsosecure.com/flutter-based-mac-osx-thick-client-ssl-pinning-bypass/