Anti-Debugging Bypass

← Insufficient Resilience

anti_debugging_bypass   HARD

Description

Debugger check is a single function trivially patched out.

How it works

A real native probe calls Debug.isDebuggerConnected() and reads the FLAG_DEBUGGABLE app flag. But the protection still collapses to a single isDebuggerAttached() return value, so an attacker NOPs it or hooks it to false and debugs freely. Toggling the check simulates patching it out.

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 Insufficient Resilience 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, r2frida, r2 · Android: gdb · iOS: lldb.
2. Locate the target. From the home index, open Anti-Debugging Bypass (anti_debugging_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. Attach an instrumentation tool (frida/objection) and hook or patch the single client-side check, confirming the protection flips to ‘pass’ and the guarded functionality unlocks.
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-0352, MASTG-TEST-0353, MASTG-TEST-0401, MASTG-TEST-0402 for the canonical procedure and remediation.

Tools (optional)

• frida
• r2frida
• r2

Android

• gdb

iOS

• lldb