WebView JS Injection + SSL-Validation Bypass

← Native / WebView Bridge (JS <-> Native)

webview_js_injection_ssl_bypass   HARD

Description

The WebView disables/relaxes TLS certificate validation (accept-all handler) while also permitting script injection, so a MITM attacker rewrites the loaded page, injects JavaScript, and escapes the WebView security boundary to reach privileged actions / steal tokens (PayRange CVE-2026-13461 class).

How it works

A WebView loads page content over a transport whose TLS certificate validation is disabled (an accept-all handler; Android onReceivedSslError -> handler.proceed(); iOS URLSession credential trust) while also permitting script injection. A MITM attacker on the path presents a forged certificate; the accept-all handler proceeds anyway, so the attacker’s rewritten page loads and its injected script calls window.bridge.getToken() and beacons the session token to the attacker (PayRange CVE-2026-13461 class). This demo boots a real WebView that runs the injected MITM script and exfiltrates the token over a JS channel, and performs a real dart:io HTTPS handshake: the accept-all client trusts a self-signed/forged cert while the validating client rejects it (in-memory panels are the offline contrast). The secure path validates the certificate against the trusted roots, so the forged cert fails and no content ever loads.

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 Native / WebView Bridge (JS <-> Native) 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, r2frida, frida, testssl.sh · Android: jadx · iOS: ipsw, class-dump.
2. Locate the target. From the home index, open WebView JS Injection + SSL-Validation Bypass (webview_js_injection_ssl_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. Reach the JS<->native bridge (or the framework/plugin API) from untrusted web content / a cross-origin iframe / a malicious provider, and confirm the privileged native call fires with no main-frame/origin, callback-id, or permission gate in between.
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-0284 for the canonical procedure and remediation.

Tools (optional)

• mitmproxy
• Burp Suite
• r2frida
• frida
• testssl.sh

Android

• jadx

iOS

• ipsw
• class-dump

Real-world references

Concrete public disclosures that match this vulnerability class:

• CVE-2026-13461 (PayRange WebView JS injection + SSL bypass)
• CVE-2026-22072 (OPPO arbitrary URL -> WebView token theft)