CVE-2020-0474 in Android
Summary
by MITRE • 12/15/2020
In HalCamera::requestNewFrame of HalCamera.cpp, there is a possible use-after-free due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-169282240
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Analysis
by VulDB Data Team • 12/18/2020
The vulnerability identified as CVE-2020-0474 resides within the Android camera HAL implementation, specifically in the HalCamera::requestNewFrame function located in HalCamera.cpp. This flaw represents a critical security weakness that stems from improper synchronization mechanisms within the camera subsystem, creating a race condition that can be exploited to execute local privilege escalation attacks. The vulnerability affects Android 11 systems and is catalogued under Android ID A-169282240, indicating its severity and the need for immediate attention from device manufacturers and security professionals.
The technical root cause of this vulnerability lies in the improper handling of memory management during camera frame requests, where a use-after-free condition occurs due to concurrent access patterns. When multiple threads attempt to access camera frame data simultaneously, the system fails to properly synchronize these operations, leading to scenarios where memory allocated to camera frame buffers may be freed while still being referenced by other processes or threads. This race condition creates a window of opportunity for malicious code to exploit the freed memory, potentially allowing an attacker with local execution privileges to manipulate the memory layout and execute arbitrary code with elevated privileges. The vulnerability specifically manifests when the HalCamera::requestNewFrame function processes incoming frame requests without adequate locking mechanisms to prevent concurrent access to shared resources.
The operational impact of CVE-2020-0474 extends beyond simple privilege escalation, as it represents a fundamental weakness in Android's camera subsystem security model. Attackers can leverage this vulnerability to gain root-level access to devices without requiring any additional privileges or user interaction, making it particularly dangerous in environments where local execution is possible. The exploitation process typically involves carefully timing memory operations to trigger the race condition, allowing the attacker to overwrite memory contents or redirect execution flow within the camera HAL process. This capability enables unauthorized access to sensitive device functions, potential data exfiltration, and the installation of persistent backdoors that can survive system reboots. The vulnerability's classification under CWE-416 (Use After Free) and its alignment with ATT&CK technique T1068 (Local Privilege Escalation) demonstrates its alignment with established security frameworks and threat modeling approaches.
Mitigation strategies for CVE-2020-0474 should focus on implementing proper synchronization mechanisms within the camera HAL implementation, including the use of mutex locks or other thread synchronization primitives to prevent concurrent access to shared memory regions. Device manufacturers should prioritize applying the latest security patches from Google, which typically include fixes that address the race condition through improved memory management and access control mechanisms. Additionally, system administrators should implement monitoring solutions that can detect anomalous camera subsystem behavior, as well as maintain strict access controls to prevent unauthorized local execution. The vulnerability's nature suggests that defensive measures should also include runtime integrity checks and memory protection mechanisms that can detect and prevent exploitation attempts. Organizations should conduct regular security assessments of their Android device configurations and ensure that all camera-related services are properly isolated and secured against potential attackers who might attempt to leverage this vulnerability for broader system compromise.