performing-mobile-app-certificate-pinning-bypass

name	performing-mobile-app-certificate-pinning-bypass
description	Bypasses SSL/TLS certificate pinning implementations in Android and iOS applications to enable traffic interception during authorized security assessments. Covers OkHttp, TrustManager, NSURLSession, and third-party pinning library bypass techniques using Frida, Objection, and custom scripts. Activates for requests involving certificate pinning bypass, SSL pinning defeat, mobile TLS interception, or proxy-resistant app testing.
domain	cybersecurity
subdomain	mobile-security
author	mahipal
tags	["mobile-security","android","ios","certificate-pinning","frida","penetration-testing"]
version	1.0.0
license	Apache-2.0
nist_csf	["PR.PS-01","PR.AA-05","ID.RA-01","DE.CM-09"]
mitre_attack	["T1059","T1056","T1036","T1078","T1027"]
source	https://github.com/mukul975/Anthropic-Cybersecurity-Skills
source_commit	04450304b12645cb2b974ab96d28c0664758a88d

Performing Mobile App Certificate Pinning Bypass

When to Use

Use this skill when:

• Mobile app refuses connections through a proxy due to certificate pinning
• Performing authorized security testing requiring HTTPS traffic interception
• Assessing the strength and bypass difficulty of pinning implementations
• Evaluating defense-in-depth of mobile app network security

Do not use to bypass pinning on apps without explicit testing authorization.

Prerequisites

• Burp Suite configured as proxy with listener on all interfaces
• Rooted Android device or jailbroken iOS device
• Frida server running on target device
• Objection installed (pip install objection)
• Target app installed and reproducing the pinning behavior

Workflow

Step 1: Identify Pinning Implementation

Android pinning methods to identify:

1. Network Security Config (res/xml/network_security_config.xml)
   <pin-set> with certificate hash pins

2. OkHttp CertificatePinner
   CertificatePinner.Builder().add("api.target.com", "sha256/...")

3. Custom TrustManager
   X509TrustManager overrides in code

4. Third-party libraries
   - TrustKit
   - Certificate Transparency checks

iOS pinning methods:

1. NSURLSession delegate (URLSession:didReceiveChallenge:)
2. ATS (App Transport Security) with custom trust evaluation
3. TrustKit framework
4. Alamofire ServerTrustPolicy
5. Custom SecTrust evaluation

Step 2: Bypass with Objection (Quickest Approach)

# Android
objection --gadget com.target.app explore
android sslpinning disable

# iOS
objection --gadget com.target.app explore
ios sslpinning disable

Objection hooks common pinning implementations including OkHttp CertificatePinner, TrustManagerImpl, NSURLSession delegate methods, and SecTrust evaluation.

Step 3: Bypass with Custom Frida Scripts

Android - Universal SSL Pinning Bypass:

// android_ssl_bypass.js
Java.perform(function() {
    // Bypass TrustManagerImpl
      = .();
    .. = () {
        .( + host);
         untrustedChain;
    };

    
     {
          = .();
        ..(, ). =
            () {
                .( + hostname);
                ;
            };
    } (e) {}

    
     X509TrustManager = .();
      = .({
        : ,
        : [X509TrustManager],
        : {
            : () {},
            : () {},
            : () {  []; }
        }
    });

    
      = .();
    ..(,
        , ). =
        () {
            .();
            .(km, [.$new()], sr);
        };

    
     {
          = .(
            );
        .. = () {
             ;
        };
    } (e) {}

    .();
});