TLS Pinning Bypass

Description

TLS pinning thwarts MITM by restricting trust to known certs/keys. Weak implementations are easily bypassed with runtime hooks, custom trust managers, or patched binaries, allowing attackers to intercept and modify API traffic.

Examples

Bypass with Objection (Android)

objection -g com.example.app explore
android sslpinning disable

Universal Frida Hook

frida -U -f com.example.app -l universal-ssl-pinning-bypass.js --no-pause

Confirm by observing decrypted traffic in a proxy:

mitmproxy -p 8080

Remediation

  1. Strong, layered pinning
    • Implement in native code; store pins/keys obfuscated; use multiple backup pins for rotation.
  2. Device integrity attestation
    • Enforce Play Integrity/SafetyNet or Apple DeviceCheck; refuse service when tampering is detected.
  3. Fail closed and monitor
    • Fail requests on pin validation errors; monitor CT logs and proxy anomalies; disallow user‑added CAs where feasible (network security config).