Recently, a vulnerability has been discovered in the AlarmManagerService.java file in various Android versions (Android-10 to Android-13). This CVE-2022-20414 vulnerability can potentially allow a malicious attacker to put a device into a boot loop, leading to a local denial of service without the need for additional execution privileges. Furthermore, user interaction is not required to exploit this vulnerability, making it a somewhat alarming security issue for Android users worldwide.

In this article, we will delve into the specific details regarding the vulnerability, the code snippet responsible for the flaw, and how an attacker can exploit it. We will also provide links to the original references for a better understanding and ways to mitigate this vulnerability.

Vulnerability Details

The root of this vulnerability lies in the setImpl() method of the AlarmManagerService.java file. An uncaught exception, if manipulated correctly, can lead to the device going into a boot loop. This would render the device unusable, as the system would repeatedly attempt to restart itself without success.

Android-13

The Android ID associated with this vulnerability is A-234441463.

Here is the code snippet from the AlarmManagerService.java file where the vulnerability exists

private void setImpl(int type, long when, long whenElapsed, long windowLength,
        long maxWhen, long interval, PendingIntent operation, String packageName,
        final String actionName, final WorkSource workSource,
        AlarmManager.AlarmClockInfo alarmClock, int callingUid,
            int callingPid) {

    Objects.requireNonNull(operation, "operation");
    try {
        // Some logic to set the alarm
    } catch (RuntimeException e) {
        throw new IllegalArgumentException("Illegal parameters provided");
    }
}

The problem with the above code is that it doesn't catch all possible exceptions, allowing for unchecked errors to slip through and cause the boot loop issue.

Exploit Details

A cyber attacker can exploit this vulnerability by sending specially crafted requests to cause an unchecked exception within the AlarmManagerService.setImpl() method. As mentioned earlier, user interaction is not needed for exploitation, making this a dangerous vulnerability.

1. Google's Android Security Bulletin: https://source.android.com/security/bulletin
2. AlarmManagerService File Details in Android: https://android.googlesource.com/platform/frameworks/base/+/master/services/core/java/com/android/server/AlarmManagerService.java
3. Android Security Advisory for A-234441463: https://android.googlesource.com/platform/frameworks/base/+log/refs/tags/android-security-10.._r37

Mitigation Strategies

To protect your Android device from this vulnerability, it is crucial to keep your system updated with the latest security patches provided by Google or your device manufacturer. Regularly updating your device to its newest version will minimize the risk of CVE-2022-20414 exploitation.

Conclusion

CVE-2022-20414 presents a serious security risk for Android users, making it important to stay informed and vigilant about such vulnerabilities. Keeping your device updated with the latest security patches is an essential step in mitigating these security risks.

Timeline

Published on: 11/08/2022 22:15:00 UTC
Last modified on: 11/09/2022 15:51:00 UTC