CVE-2021-0306 Explained : Impact and Mitigation

This article provides a detailed insight into CVE-2021-0306, a vulnerability affecting Android that allows an app to gain specific permissions without user confirmation, potentially leading to a local privilege escalation.

Understanding CVE-2021-0306

CVE-2021-0306 is a vulnerability in Android that resides in the addAllPermissions function of PermissionManagerService.java. It enables an app to acquire the android.permission.ACTIVITY_RECOGNITION permission during major Android version upgrades without user consent. This loophole can be exploited for local privilege escalation without requiring additional execution privileges.

What is CVE-2021-0306?

The vulnerability in addAllPermissions of PermissionManagerService.java in Android could be exploited by a malicious app to attain the android.permission.ACTIVITY_RECOGNITION permission during major Android version upgrades without the user's confirmation. This flaw allows for local escalation of privilege with no further execution privileges needed, and no user interaction is required for exploitation.

The Impact of CVE-2021-0306

The impact of CVE-2021-0306 is the potential elevation of privilege for a malicious app on Android devices. By exploiting this vulnerability, the app can bypass user confirmation and gain sensitive permissions, leading to unauthorized access and potential security breaches.

Technical Details of CVE-2021-0306

The technical details of CVE-2021-0306 include:

Vulnerability Description

The vulnerability lies in the addAllPermissions function of PermissionManagerService.java in Android. It allows apps to acquire the android.permission.ACTIVITY_RECOGNITION permission during major Android version upgrades without user consent.

Affected Systems and Versions

The affected versions include Android-11, Android-8.0, Android-8.1, Android-9, and Android-10. Devices running these versions are at risk of exploitation.

Exploitation Mechanism

Exploiting CVE-2021-0306 does not require user interaction. A malicious app can leverage this vulnerability to bypass user confirmation and escalate its privileges locally on the device.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-0306, consider the following steps:

Immediate Steps to Take

Update Android devices to the latest patched versions provided by the vendor.
Avoid downloading apps from untrusted sources to minimize the risk of malicious exploitation.

Long-Term Security Practices

Regularly update the device's operating system to ensure the latest security features and patches are implemented.
Implement app permission restrictions to control access and reduce the impact of potential vulnerabilities.

Patching and Updates

Stay informed about security bulletins and patches released by the official Android security team and apply them promptly to safeguard against known vulnerabilities.