CVE-2021-0656 in MT6853
Summary
by MITRE • 11/18/2021
In edma driver, 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: ALPS05709376; Issue ID: ALPS05709376.
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Analysis
by VulDB Data Team • 11/22/2021
The vulnerability identified as CVE-2021-0656 resides within the edma driver component of a mobile operating system, specifically affecting devices running on the android platform. This memory corruption flaw manifests as a use after free condition that occurs when the driver improperly handles memory allocation and deallocation sequences. The edma driver is responsible for managing data movement operations between various hardware components and memory subsystems, making it a critical component in the system's overall security architecture. The vulnerability was tracked under patch ID ALPS05709376 and issue ID ALPS05709376, indicating it was addressed within the android platform's security update cycle.
The technical nature of this vulnerability stems from improper memory management within the edma driver's codebase, where freed memory blocks are accessed after being deallocated. This use after free condition creates a predictable memory layout that can be exploited by malicious code to manipulate system behavior. When the driver processes certain data operations, it may free memory resources while still maintaining pointers to those locations, allowing subsequent operations to access the now-invalidated memory regions. The vulnerability specifically affects the driver's handling of memory allocation requests and subsequent deallocation processes, creating opportunities for attackers to inject malicious code or manipulate system state.
The operational impact of CVE-2021-0656 represents a significant local privilege escalation vulnerability that allows attackers with minimal user interaction to gain system-level privileges. While the exploitation does not require user interaction, it necessitates that the attacker already possesses system execution privileges, typically meaning they must have already compromised a user-level process or gained access to the device through other means. Once exploited, this vulnerability could enable attackers to execute arbitrary code with the highest system privileges, potentially allowing complete system compromise including access to all user data, device functionality, and security mechanisms. The vulnerability's classification as a local privilege escalation means it could be leveraged to bypass security controls that normally protect system integrity and user privacy.
Mitigation strategies for this vulnerability primarily involve applying the official security patch provided under ALPS05709376, which addresses the memory management issues within the edma driver. System administrators should prioritize deploying the patch across all affected devices and verify that the update has been successfully applied. Additionally, organizations should implement monitoring systems to detect potential exploitation attempts, particularly focusing on anomalous memory access patterns or unexpected driver behavior. The vulnerability aligns with CWE-416, which specifically addresses use after free conditions in memory management, and represents a potential ATT&CK technique under privilege escalation tactics. Regular security assessments of driver components and memory management practices should be conducted to identify similar vulnerabilities that may exist within other system components.