CVE-2021-1046 in Android
Summary
by MITRE • 12/15/2021
In lwis_dpm_update_clock of lwis_device_dpm.c, 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.Product: AndroidVersions: Android kernelAndroid ID: A-195609074References: N/A
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Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-1046 resides within the Linux kernel's lwis_dpm_update_clock function located in the lwis_device_dpm.c source file. This flaw represents a classic out-of-bounds read condition that emerges from an inadequate bounds check implementation. The vulnerability specifically affects Android kernel implementations and carries the Android ID A-195609074 for tracking purposes. The issue stems from improper validation of array indices or buffer boundaries during clock update operations, creating a scenario where the kernel attempts to access memory locations beyond the allocated buffer limits.
The technical nature of this vulnerability places it squarely within CWE-129, which addresses improper validation of array indices, and CWE-131, which covers incorrect calculation of buffer or object boundaries. The flaw manifests as a potential information disclosure channel that requires system execution privileges for exploitation, indicating that an attacker must already possess elevated privileges or have access to a system with system-level capabilities. This privilege requirement suggests the vulnerability may be exploited through a local attacker who has already gained a foothold on the system, potentially through a previous compromise or legitimate administrative access.
From an operational impact perspective, this vulnerability could enable unauthorized information disclosure within the kernel space, potentially exposing sensitive system data, memory contents, or configuration parameters that should remain protected. The local information disclosure aspect means that an attacker with system execution privileges could leverage this flaw to extract confidential data from kernel memory regions. The absence of user interaction requirements for exploitation indicates that the vulnerability can be triggered automatically once the attacker has system-level access, making it particularly concerning for environments where privileged access might be compromised. This type of vulnerability undermines the kernel's memory safety mechanisms and could potentially serve as a stepping stone for more sophisticated attacks.
Mitigation strategies should focus on implementing proper bounds checking mechanisms within the lwis_dpm_update_clock function to ensure that all array accesses are validated against legitimate buffer boundaries. The fix would require developers to enhance the existing validation logic to properly check array indices before any memory access operations occur. Additionally, implementing robust input validation and boundary checks throughout the kernel codebase, particularly in device driver implementations, would help prevent similar issues from arising. System administrators should ensure that kernel updates are applied promptly to address this vulnerability, and security monitoring should be enhanced to detect any anomalous memory access patterns that might indicate exploitation attempts. The vulnerability also highlights the importance of code review practices specifically focused on memory safety and bounds checking in kernel space operations, aligning with ATT&CK technique T1068 which involves exploiting local privileges and T1547.001 which covers registry run keys and startup folder modifications that could be used to establish persistence following successful exploitation.