CVE-2021-0900 in MT6873
Summary
by MITRE • 12/17/2021
In apusys, there is a possible out of bounds read due to an incorrect bounds check. This could lead to local information disclosure with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS05672107; Issue ID: ALPS05672055.
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Analysis
by VulDB Data Team • 12/24/2021
The vulnerability identified as CVE-2021-0900 resides within the apusys component of a mobile operating system, specifically affecting Android-based devices. This issue represents a classic out-of-bounds read condition that occurs when the system fails to properly validate array indices or buffer limits during memory operations. The flaw manifests in the apusys module which typically handles system-level processes and kernel operations, making it a critical component for device security and stability.
The technical root cause of this vulnerability stems from an incorrect bounds check implementation within the memory management routines of apusys. When processing certain data structures or system calls, the module performs array access operations without adequate validation of the indices being used. This allows an attacker to potentially access memory locations beyond the intended boundaries, resulting in information disclosure. The vulnerability is classified as CWE-129 in the Common Weakness Enumeration catalog, which specifically addresses insufficient bounds checking in array access operations.
The operational impact of this vulnerability is significant as it enables local information disclosure when exploited with system execution privileges. While the vulnerability does not require user interaction for exploitation, it still necessitates that an attacker already possess system-level privileges or be able to escalate to such a level. This typically means an attacker would need to have already compromised the device or gained access through other means before leveraging this specific vulnerability. The information disclosure could potentially expose sensitive system data, kernel memory contents, or other confidential information that could aid in further exploitation attempts.
The patch ID ALPS05672107 and associated issue ID ALPS05672055 indicate this vulnerability was addressed through a system-level update specifically targeting the apusys module. This aligns with the ATT&CK framework's concept of privilege escalation and credential access, where attackers may exploit system vulnerabilities to gain deeper access to device resources. The vulnerability's classification as a local information disclosure means it fits within the attack pattern of information gathering and reconnaissance activities that precede more sophisticated attacks.
Mitigation strategies for this vulnerability primarily involve applying the official patch provided by the device manufacturer, which typically addresses the bounds checking logic in the apusys module. Organizations and users should prioritize updating their devices to the patched version as soon as possible. Additionally, system administrators should implement monitoring for unusual memory access patterns or potential exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper bounds checking in system-level code and demonstrates how seemingly minor implementation flaws in kernel modules can create significant security risks. Regular security audits of system components, particularly those handling memory operations and system calls, are essential for identifying similar vulnerabilities before they can be exploited by malicious actors.