Certificate Pinning Bypass

Certificate Pinning Bypass refers to techniques used to circumvent certificate pinning protections in mobile apps or clients, allowing man-in-the-middle interception of HTTPS traffic for security testing or malicious purposes.

What is Certificate Pinning?

Certificate pinning is a security measure where applications only trust specific certificates or public keys, rather than any certificate signed by a trusted CA. This prevents MITM attacks even if an attacker has a valid CA-signed certificate.

Common Bypass Techniques

Runtime Instrumentation (Frida)

// Frida script to bypass pinning
Java.perform(function() {
    var TrustManager = Java.use('javax.net.ssl.X509TrustManager');
    TrustManager.checkServerTrusted.implementation = function() {
        return;  // Accept all certificates
    };
});

Tools for Bypassing

  • Frida: Dynamic instrumentation toolkit
  • Objection: Runtime mobile exploration
  • SSLUnpinning: Xposed/Magisk modules
  • apk-mitm: Automated APK patching

Binary Patching

  • Modify the app binary to remove pinning checks
  • Replace pinned certificates with attacker's certificate
  • Disable certificate validation functions

Legitimate Use Cases

  • Security testing of mobile applications
  • Debugging network traffic during development
  • Security research and vulnerability assessment

See Also