CVE-2021-0493 in Android
Summary
by MITRE • 06/11/2021
In memory management driver, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android SoCAndroid ID: A-183461317
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Analysis
by VulDB Data Team • 06/18/2021
The vulnerability identified as CVE-2021-0493 resides within the memory management driver component of Android operating systems, representing a critical security flaw that could enable local privilege escalation without requiring additional execution privileges or user interaction. This issue manifests as a missing bounds check in the memory management driver, creating a potential out of bounds write condition that adversaries can exploit to gain elevated system privileges. The vulnerability affects Android SoC implementations and has been assigned the Android ID A-183461317, indicating its significance within the Android security framework.
The technical flaw stems from inadequate input validation within the memory management driver's code structure, where proper bounds checking mechanisms have been omitted during memory allocation or manipulation operations. When the system processes memory management requests, it fails to verify that write operations remain within allocated memory boundaries, allowing malicious code to overwrite adjacent memory locations. This missing bounds check creates a pathway for attackers to manipulate critical system memory regions, potentially corrupting kernel data structures or overwriting privilege-related variables. The vulnerability operates at the kernel level within the memory management subsystem, making it particularly dangerous as it can directly impact the operating system's core memory handling capabilities.
The operational impact of CVE-2021-0493 extends beyond simple memory corruption, as it enables local privilege escalation through a direct manipulation of the kernel's memory management functions. An attacker with local access to an Android device can leverage this vulnerability to elevate their privileges from standard user level to system level without requiring additional attack vectors or elevated execution rights. This makes the exploit particularly concerning for mobile environments where local access is often achievable through various means such as malicious applications or compromised user accounts. The lack of user interaction requirement for exploitation means that the vulnerability can be triggered automatically, potentially allowing for automated privilege escalation attacks that could compromise the entire device. The memory management driver's role in system stability makes this vulnerability particularly dangerous as it could lead to system crashes, data corruption, or complete device compromise.
Mitigation strategies for CVE-2021-0493 should focus on immediate patch deployment from device manufacturers, as this vulnerability represents a critical kernel-level flaw requiring system-level fixes. Organizations should prioritize updating Android devices to versions containing the patched memory management driver components, with particular attention to devices running affected Android SoC implementations. Security teams should implement continuous monitoring for unauthorized privilege escalation attempts and maintain detailed logging of memory management operations to detect potential exploitation attempts. The vulnerability's classification as a memory safety issue aligns with CWE-129, which addresses improper bounds checking in memory operations, and its exploitation patterns correspond to ATT&CK technique T1068, which covers local privilege escalation through kernel exploits. Device manufacturers should also consider implementing additional runtime protections such as stack canaries, address space layout randomization, and kernel address space layout randomization to further reduce the exploitability of similar memory corruption vulnerabilities.