In the fast-evolving world of smartphones and IoT gadgets, Qualcomm's Snapdragon chips are everywhere—from mobile phones to wearables and smart home devices. But with great popularity comes risk. One of the most notorious vulnerabilities discovered in recent years is CVE-2022-25679, a denial-of-service (DoS) flaw rooted in poor access control in Android's broadcast receivers. In this article, let’s break down what that means, how it works, and why it matters using simple language and real code examples.

Snapdragon Wearables

The flaw *allows a local attacker (an app or malicious code on your device)* to cause a denial of service (DoS), especially in video features. This happens because some system components, specifically the broadcast receivers, didn't check if incoming requests were coming from trusted sources.

Broadcast Receivers and Access Controls (A Quick Refresher)

Broadcast Receivers are a type of Android component that listens for system-wide messages (broadcasts) like *battery low*, *picture taken*, or even custom app messages. Normally, sensitive receivers should only accept messages from trusted apps or users.

But in Snapdragon’s software, due to improper access checks, *any app* could shout at these sensitive receivers—including code that could mess up your device, crash video playback, or kill camera functions.

How Does the Attack Work?

A malicious app can send a carefully crafted broadcast message to a vulnerable receiver. Since there's no access control, the receiver processes the message, possibly performing dangerous operations or entering an unstable state, resulting in a video service crash or even a complete system reboot.

Real-World Example: Exploiting CVE-2022-25679

Let’s look at a simplified example. Imagine the vulnerable broadcast receiver is registered in Qualcomm’s video subsystem (this is hypothetical, to protect proprietary Qualcomm code):

<receiver
    android:name=".SnapdragonVideoReceiver"
    android:exported="true">
    <intent-filter>
        <action android:name="com.qualcomm.SEND_VIDEO_CMD"/>
    </intent-filter>
</receiver>

Notice android:exported="true"? This means apps from outside can talk to this receiver.

A basic PoC in Java or Kotlin could look like this

Intent intent = new Intent();
intent.setAction("com.qualcomm.SEND_VIDEO_CMD");
intent.putExtra("cmd", "crash_video");
context.sendBroadcast(intent);

Or via adb (Android Debug Bridge)

adb shell am broadcast -a com.qualcomm.SEND_VIDEO_CMD --es cmd "crash_video"

If the receiver does not check *who* is sending the intent, it will process it—possibly with catastrophic results:

Kill your video or camera app suddenly

- Prevent the device from recording/playing videos

Force the device to reboot (worst case!)

This is not a *remote hack*, but any app installed with standard permissions could attempt it.

Receivers have android:exported="false" or enforce custom permission checks.

Mitigation tip: Always keep your devices up-to-date with the latest firmware and security patches.

- CVE Page: CVE-2022-25679
- Qualcomm Security Bulletin: June 2023 Security Bulletin
- Google Android Docs: BroadcastReceiver Security
- Mitigation Techniques: Android Exported Attribute

Conclusion

CVE-2022-25679 is a reminder that *internal security mistakes* (like poor access control) can have big, visible consequences, including taking out your video or camera with a simple broadcast message. If you're a developer, always check sender permissions! If you're a user, keep your device updated and avoid installing suspicious apps.

Timeline

Published on: 11/15/2022 10:15:00 UTC
Last modified on: 04/19/2023 17:10:00 UTC