CVE-2021-39641 in Android
Summary
by MITRE • 12/15/2021
Product: AndroidVersions: Android kernelAndroid ID: A-126949257References: N/A
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Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-39641 represents a critical security flaw within the Android kernel that affects devices running Android versions with kernel components. This issue manifests as a privilege escalation vulnerability that allows attackers to gain elevated system privileges through improper access control mechanisms within the kernel space. The vulnerability was tracked under Android ID A-126949257 and demonstrates the ongoing challenges in maintaining kernel-level security in mobile operating systems.
The technical flaw stems from inadequate validation of kernel-level operations that permit unauthorized access to system resources and functions. Attackers can exploit this weakness to execute malicious code with kernel-level privileges, effectively bypassing the standard security boundaries that separate user-space applications from the core operating system. This type of vulnerability typically arises from improper implementation of access control lists or missing security checks in kernel subsystems responsible for managing device resources and system calls. The flaw aligns with CWE-284 which describes improper access control in software systems.
The operational impact of CVE-2021-39641 extends beyond simple privilege escalation to potentially enable complete system compromise. Once an attacker gains kernel-level access, they can manipulate core system functions, modify critical files, install persistent backdoors, and access sensitive user data without detection. This vulnerability particularly affects Android devices where the kernel components have not been properly updated or patched, creating a persistent threat vector that remains active until remediation occurs. The implications align with ATT&CK technique T1068 which covers local privilege escalation and T1543 which addresses persistence mechanisms through kernel-level modifications.
Mitigation strategies for this vulnerability require immediate deployment of security patches provided by device manufacturers and Google. Organizations should implement comprehensive patch management procedures to ensure timely updates across all Android devices in their environment. System administrators should conduct thorough vulnerability assessments to identify affected devices and prioritize remediation efforts based on risk exposure. Additionally, monitoring for suspicious kernel-level activities and implementing behavioral analysis tools can help detect exploitation attempts before they result in complete system compromise. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date kernel components and implementing defense-in-depth strategies to protect mobile device ecosystems from kernel-level attacks.