SSL Pinning (Trivially Bypassable)

← Insecure Communication

ssl_pinning_bypass   HARD

CategoryInsecure Communication
OWASP Mobile (2024)M5
MASVSMASVS-NETWORK-2
MASWEMASWE-0028
MASTG (v2 tests)iOSNone publishedAndroidMASTG-TEST-0244MASTG-TEST-0242
CWECWE-295
PlatformAndroidiOS

Description

Pinning is implemented but disabled by a client-side flag / easy hook.

How it works

Certificate pinning is implemented but gated behind a mutable client-side flag and a single checkPin() function. An attacker flips the flag or hooks the function to return true (frida or objection), and a Burp/mitmproxy certificate sails through. It makes a real TLS connection: toggle pinning off via the hook and the MITM certificate is accepted; leave it on and the handshake is rejected.

How to exercise it. DVMA is the harness - open this module from the home index and tap the demo action. The screen ships the malicious input and simulates the attacker (e.g. the companion app, crafted intent, or scanned payload) in-process, and the evidence panel prints the proof. The Tools (optional) and Attack inputs below are only needed to reproduce the exploit end-to-end on a real device.

Exploit steps

  1. Set up. Build DVMA with a flavor that enables the Insecure Communication category (e.g. --dart-define-from-file=config/flavors/dev.json) and run on an emulator/simulator you control. The demo needs no external tooling; for the optional on-device reproduction the relevant tools are: frida, objection, r2frida, mitmproxy, Burp Suite.
  2. Locate the target. From the home index, open SSL Pinning (Trivially Bypassable) (ssl_pinning_bypass). The How it works section above describes this module’s specific weakness; the screen states the intended-secure behavior and exposes the vulnerable action.
  3. Exploit. Route the app through an intercepting proxy (Burp/mitmproxy) with your CA installed, trigger the network call, and confirm you can read or modify traffic (cleartext, weak TLS, or a trivially-bypassed pin).
  4. Observe the evidence. Trigger the vulnerable action and read the evidence panel - it prints the concrete proof (leaked value, accepted replay, executed payload, or unauthorized result).
  5. Contrast with the secure path. Run the module’s secure/hardened action (where provided) and confirm the same attack is rejected - this is what a correct implementation should do.
  6. Map it back. Cross-reference the MASTG v2 test(s) MASTG-TEST-0244, MASTG-TEST-0242 for the canonical procedure and remediation.

Tools (optional)