CVE-2021-0670 in MT6853
Summary
by MITRE • 11/18/2021
In apusys, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS05654663; Issue ID: ALPS05654663.
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Analysis
by VulDB Data Team • 11/22/2021
The vulnerability identified as CVE-2021-0670 resides within the apusys component of Android systems, representing a critical memory corruption flaw that manifests as a use after free condition. This type of vulnerability occurs when a program continues to reference memory locations after they have been freed, creating opportunities for malicious code execution. The flaw specifically affects the apusys subsystem which manages audio processing and system audio services, making it particularly dangerous as it operates within the kernel space of the operating system. The vulnerability is classified under CWE-416 as Use After Free, a well-documented weakness that has been exploited in numerous security incidents across various platforms. The issue is particularly concerning because it enables local privilege escalation, allowing an attacker with system execution privileges to elevate their access level within the system.
The technical exploitation of this vulnerability requires an attacker to have already gained system execution privileges, which typically means they have achieved a foothold through another attack vector or have legitimate system access. However, the absence of user interaction requirements makes this vulnerability particularly dangerous as it can be exploited automatically without any user involvement. The use after free condition in apusys allows for memory corruption that can be leveraged to execute arbitrary code with elevated privileges, potentially leading to complete system compromise. This type of vulnerability is classified under the ATT&CK framework as privilege escalation through memory corruption techniques, specifically targeting kernel-level components to gain elevated system access.
The operational impact of CVE-2021-0670 extends beyond simple local privilege escalation, as it represents a significant security weakness in the Android operating system's audio subsystem management. When exploited successfully, the vulnerability can enable attackers to gain full system control, potentially allowing them to access sensitive data, modify system files, install malicious software, or create persistent backdoors. The vulnerability affects devices running specific versions of Android where the apusys component is present, making it particularly relevant for device manufacturers and security professionals managing Android-based systems. The patch ID ALPS05654663 indicates that this vulnerability was addressed through a specific software update that corrected the memory management issues within the apusys subsystem.
Mitigation strategies for this vulnerability should focus on immediate patch deployment as the primary defense mechanism, ensuring that all affected Android devices receive the necessary software updates. Organizations should also implement monitoring systems to detect potential exploitation attempts, particularly focusing on anomalous memory access patterns and privilege escalation activities. Security teams should conduct thorough vulnerability assessments of their Android device fleets to identify systems running affected software versions. The remediation process should include not only patching but also network monitoring to detect any attempts to exploit this vulnerability, as well as maintaining updated threat intelligence feeds that may indicate active exploitation attempts. Additionally, implementing principle of least privilege configurations and regular security audits can help minimize the potential impact should the vulnerability be exploited in environments where patching cannot be immediately deployed.