CVE-2021-0970 in Android
Summary
by MITRE • 12/15/2021
In createFromParcel of GpsNavigationMessage.java, there is a possible Parcel serialization/deserialization mismatch. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10 Android-11 Android-12 Android-9Android ID: A-196970023
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-0970 resides within the Android operating system's GPS navigation message handling component, specifically in the createFromParcel method of the GpsNavigationMessage.java file. This flaw represents a critical security weakness that exploits inconsistencies in the parcel serialization and deserialization processes, creating a pathway for unauthorized privilege escalation. The vulnerability affects multiple Android versions including Android 9, 10, 11, and 12, indicating a widespread impact across the Android ecosystem. The nature of this vulnerability places it squarely within the category of local privilege escalation issues, where an attacker can elevate their privileges without requiring additional execution privileges or user interaction, making it particularly dangerous in environments where applications may have elevated permissions.
The technical root cause of this vulnerability stems from improper handling of parcel data structures during the deserialization process. When the system attempts to reconstruct objects from parcel data, the mismatch between how data is serialized and how it is subsequently deserialized creates opportunities for memory corruption or unexpected behavior. This type of flaw commonly falls under CWE-121, which describes stack-based buffer overflow conditions, or CWE-122, which addresses heap-based buffer overflow conditions, depending on the specific memory corruption pattern. The Android framework's parcel mechanism is designed to efficiently transfer data between processes, but when the deserialization logic does not properly validate the incoming data structure against the expected object layout, it opens the door for malicious manipulation of memory contents.
The operational impact of CVE-2021-0970 extends beyond simple privilege escalation, as it represents a fundamental weakness in Android's security model that could allow attackers to gain unauthorized access to system resources and potentially execute arbitrary code with elevated privileges. This vulnerability aligns with the ATT&CK framework's privilege escalation techniques, specifically targeting the 'Local Privilege Escalation' tactic where adversaries seek to gain higher-level permissions on compromised systems. The lack of user interaction requirement makes this vulnerability particularly concerning for mobile environments where applications may already have access to sensitive system APIs and user data. Attackers could exploit this vulnerability to access GPS data, modify system configurations, or potentially gain root access to the device, depending on the specific implementation details and the privileges of the calling process.
Mitigation strategies for CVE-2021-0970 should focus on immediate system updates and patches provided by Google and device manufacturers, as the vulnerability affects core Android framework components that require official security updates to address. Organizations should prioritize patching affected Android devices, particularly those running versions 9 through 12, to prevent exploitation. Additionally, implementing network monitoring and behavioral analysis can help detect potential exploitation attempts by monitoring for unusual parcel data handling patterns or unexpected privilege escalation events. The vulnerability also underscores the importance of secure coding practices in Android development, particularly around the proper validation of parcel data structures and the implementation of robust input sanitization mechanisms. Security teams should conduct thorough vulnerability assessments of their Android applications to ensure proper handling of parcel data and avoid similar issues in custom implementations. The remediation process should include comprehensive testing of parcel serialization and deserialization logic to validate that all data structures are properly validated before processing, reducing the risk of similar vulnerabilities in future deployments.