CVE-2025-68709 Overview
CVE-2025-68709 affects SailingLab AppLock (com.alpha.applock) version 4.3.8 for Android. The application exposes BrowserMainActivity, which accepts VIEW intents containing javascript: URIs without validation. A local attacker on the device can craft an intent that triggers arbitrary JavaScript execution inside the app's WebView context. This unsafe navigation path can enable user interface (UI) spoofing or privilege escalation within the application boundary. The vulnerability is classified as Cross-Site Scripting [CWE-79] in the context of a mobile WebView. AppLock is distributed through the Google Play Store and is installed on Android user devices that rely on it to lock other applications.
Critical Impact
A local attacker can execute arbitrary JavaScript inside AppLock's WebView, enabling UI spoofing and potential privilege escalation within the app's protected context.
Affected Products
- SailingLab AppLock (com.alpha.applock) version 4.3.8
- Android installations distributed via Google Play
- BrowserMainActivity component handling VIEW intents
Discovery Timeline
- 2026-05-26 - CVE-2025-68709 published to NVD
- 2026-05-27 - Last updated in NVD database
Technical Details for CVE-2025-68709
Vulnerability Analysis
The flaw resides in the BrowserMainActivity component of AppLock 4.3.8. The activity is exported or otherwise reachable from other applications on the device and accepts android.intent.action.VIEW intents. When the intent's data URI uses the javascript: scheme, the activity loads the URI directly into its WebView. The WebView then evaluates the script in the context of the AppLock application. Because AppLock is the component responsible for locking and unlocking other apps, script execution inside its WebView breaks the security boundary the user expects.
Root Cause
The root cause is missing scheme validation on incoming intent data before passing it to the WebView's loadUrl flow. The component treats untrusted external input as a trusted URL and does not strip or reject javascript: URIs. This is a classic Client-Side Injection issue in Android, mapped to [CWE-79]. The WebView configuration permits JavaScript execution, which converts an unvalidated navigation request into script execution.
Attack Vector
Exploitation requires a local attacker, typically a malicious or compromised app already installed on the same device, or physical access that allows launching an intent through adb. The attacker constructs an intent targeting com.alpha.applock/.BrowserMainActivity with a javascript: payload as the data URI. User interaction is required to complete the navigation in the WebView. Once executed, the script runs with access to the WebView's DOM and any exposed JavaScript interfaces, enabling spoofed prompts that mimic AppLock's unlock UI or actions that elevate access within the app. Verified technical details and proof-of-concept material are documented in the GitHub CVE-2025-68709 Details repository.
Detection Methods for CVE-2025-68709
Indicators of Compromise
- Intents directed at com.alpha.applock/.BrowserMainActivity containing data URIs that begin with javascript:.
- Installed AppLock package com.alpha.applock at version 4.3.8 on managed Android devices.
- Unexpected WebView navigation events or script errors logged by AppLock around unlock-prompt interactions.
Detection Strategies
- Inventory Android endpoints through mobile device management (MDM) to flag installations of com.alpha.applock version 4.3.8.
- Inspect AndroidManifest.xml of the installed APK for an exported BrowserMainActivity with VIEW intent filters.
- Use Android logcat or dynamic analysis tools to detect WebView loadUrl calls receiving javascript: schemes from external intents.
Monitoring Recommendations
- Monitor MDM telemetry for installation or update events of the affected AppLock version on corporate devices.
- Alert on any other application on the device issuing VIEW intents with javascript: URIs targeting locker or security apps.
- Track Google Play update channels for a vendor patch superseding version 4.3.8.
How to Mitigate CVE-2025-68709
Immediate Actions Required
- Uninstall AppLock 4.3.8 (com.alpha.applock) from managed Android devices until a fixed version is published.
- Restrict installation of unvetted third-party applications that could deliver the malicious intent.
- Review device app inventories and remove other applications from untrusted sources running alongside AppLock.
Patch Information
No vendor patch is referenced in the published advisory. Monitor the Google Play App Listing and the GitHub Project Repository for an updated release that validates intent data and rejects javascript: URIs in BrowserMainActivity.
Workarounds
- Replace AppLock with an alternative locker application that does not expose an unvalidated WebView entry point.
- Enforce MDM policy that blocks sideloading and limits installs to a curated allowlist.
- For developers maintaining similar code, validate the intent data scheme and reject any URI not in an explicit allowlist before calling WebView.loadUrl.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
