CVE-2021-0498 in Android
Summary
by MITRE • 06/11/2021
In memory management driver, there is a possible memory corruption due to a double free. 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-183461321
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Analysis
by VulDB Data Team • 06/18/2021
The vulnerability identified as CVE-2021-0498 resides within the memory management driver component of Android operating systems, representing a critical security flaw that could be exploited for local privilege escalation. This issue manifests as a double free condition in the kernel-level memory management subsystem, where the same memory block gets freed twice, potentially leading to memory corruption that adversaries can leverage to gain elevated privileges. The vulnerability affects Android SoC implementations and has been assigned the Android ID A-183461321, indicating its severity and the need for immediate attention from device manufacturers and system administrators.
The technical root cause of this vulnerability stems from improper memory management handling within the kernel driver responsible for memory allocation and deallocation operations. When the system attempts to free memory that has already been freed, the memory management structures become corrupted, creating a potential attack surface for privilege escalation. This double free condition occurs in the memory management driver, which is responsible for handling memory operations at the kernel level where the system maintains strict access controls and privilege boundaries. The flaw demonstrates a classic memory corruption vulnerability pattern that aligns with CWE-415, which describes improper handling of memory allocation and deallocation operations. Such conditions can lead to arbitrary code execution within kernel space, as the corrupted memory structures may allow attackers to manipulate the execution flow of the system.
The operational impact of CVE-2021-0498 is particularly concerning as it enables local privilege escalation without requiring any additional execution privileges or user interaction for exploitation. This means that an attacker with regular user-level access to a device could potentially leverage this vulnerability to gain root-level privileges, effectively bypassing all security controls and access restrictions. The vulnerability's exploitation does not require user interaction, making it especially dangerous as it can be triggered automatically when the affected memory management operations occur. The implications extend beyond simple privilege escalation, as the attacker could then access sensitive system data, modify critical system files, install malicious software, or disable security features entirely. This vulnerability directly impacts the fundamental security model of Android systems, where kernel-level memory management is critical for maintaining system integrity and user security boundaries.
Mitigation strategies for CVE-2021-0498 should prioritize immediate patch deployment from device manufacturers and system vendors, as this vulnerability represents a high-severity threat that can be exploited without user interaction. The fix typically involves implementing proper memory management checks within the kernel driver to prevent double free conditions by ensuring memory blocks are properly tracked and validated before deallocation. Security professionals should also consider implementing runtime monitoring and anomaly detection for memory management operations, as outlined in the ATT&CK framework's memory corruption techniques. Additional defensive measures include maintaining up-to-date system patches, implementing kernel module integrity checks, and conducting regular security assessments of memory management subsystems. Organizations should also consider employing exploit prevention techniques such as stack canaries, address space layout randomization, and kernel address space layout randomization to make exploitation more difficult even if the underlying vulnerability is not patched immediately. The vulnerability underscores the importance of proper memory management practices in kernel-level code development and highlights the critical need for thorough security testing of memory management subsystems in mobile operating systems.