Accept-All TrustManager

← Insecure Communication

accept_all_trust_manager   MEDIUM

Description

Custom certificate callback accepts any certificate.

How it works

The app installs an HttpClient.badCertificateCallback that returns true for every certificate and host, the Dart equivalent of an empty X509TrustManager. It makes an HTTPS request with validation off, so a Burp/mitmproxy self-signed certificate is accepted and the “TLS” traffic is intercepted.

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: mitmproxy, Burp Suite, testssl.sh.
2. Locate the target. From the home index, open Accept-All TrustManager (accept_all_trust_manager). 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-0282, MASTG-TEST-0283 for the canonical procedure and remediation.

Tools (optional)

• mitmproxy
• Burp Suite
• testssl.sh