CVE-2021-1040 in Android
Summary
by MITRE • 12/15/2021
In onCreate of BluetoothPairingSelectionFragment.java, there is a possible EoP due to a tapjacking/overlay attack. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-10 Android-11 Android-12 Android-9Android ID: A-182810085
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-1040 represents a critical privilege escalation flaw within the Android Bluetooth pairing functionality that operates at the framework level. This issue exists within the onCreate method of BluetoothPairingSelectionFragment.java, a component that handles the user interface for Bluetooth device pairing operations. The vulnerability stems from inadequate protection against overlay attacks and tapjacking techniques that allow malicious applications to deceive users into interacting with hidden or disguised interface elements. The flaw specifically affects Android versions 9 through 12, encompassing a significant portion of the mobile ecosystem where Bluetooth pairing operations occur.
The technical nature of this vulnerability aligns with CWE-691, which addresses inadequate protection against overlay attacks, and represents a sophisticated attack vector that exploits the trust relationship between users and the Android operating system. When a user interacts with what appears to be a legitimate Bluetooth pairing interface, an attacker can potentially overlay malicious elements that capture user input or trigger unintended actions. The attack requires user interaction to be successful, typically involving a carefully crafted overlay that mimics the legitimate pairing interface while containing hidden malicious functionality. This tapjacking approach capitalizes on the fact that the Bluetooth pairing fragment does not adequately validate the authenticity of the interface elements presented to the user.
The operational impact of this vulnerability is severe as it enables local escalation of privilege without requiring any additional execution privileges or malicious code installation. An attacker who successfully executes this attack can gain elevated system privileges, potentially allowing them to access sensitive user data, modify system configurations, or escalate their access to other applications and services running on the device. The implications extend beyond simple data theft to include complete system compromise, as the attacker can leverage the elevated privileges to manipulate core system functions and potentially install persistent backdoors. This vulnerability particularly affects the Android Bluetooth framework's security model, where the trust boundary between legitimate system components and user interface elements becomes compromised.
Mitigation strategies for CVE-2021-1040 should focus on implementing robust overlay protection mechanisms and user interface validation techniques that prevent malicious applications from creating deceptive interfaces during critical system operations. Android security updates typically address such issues by strengthening the verification processes for UI elements and implementing additional checks to detect and prevent overlay attacks. Organizations should ensure immediate patch deployment for affected Android versions and consider implementing additional security controls such as user interface integrity monitoring and behavioral analysis to detect anomalous overlay activities. The vulnerability also highlights the importance of following ATT&CK framework principles for mobile security, particularly the techniques related to privilege escalation and user interface manipulation that attackers can leverage to compromise system integrity.