CVE-2022-20571 in Android
Summary
by MITRE • 12/16/2022
In extract_metadata of dm-android-verity.c, there is a possible way to corrupt kernel memory due to a use after free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-234030265References: Upstream kernel
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability identified as CVE-2022-20571 resides within the dm-android-verity.c component of the Android kernel, specifically within the extract_metadata function. This flaw represents a critical use-after-free condition that can potentially compromise kernel memory integrity. The vulnerability is particularly concerning as it enables local privilege escalation, requiring only system execution privileges for exploitation. Unlike many kernel vulnerabilities that demand user interaction, this issue can be triggered automatically, making it especially dangerous in mobile environments where kernel-level access is typically restricted.
The technical nature of this vulnerability stems from improper memory management within the device mapper android verity subsystem. When the extract_metadata function processes metadata structures, it fails to properly validate memory references before subsequent operations, creating opportunities for memory corruption. This use-after-free condition occurs when the kernel attempts to access memory that has already been freed, potentially allowing malicious code to manipulate kernel data structures or overwrite critical function pointers. The flaw exists in the Android kernel's handling of verity metadata, which is used to verify the integrity of system partitions and prevent unauthorized modifications to critical system components.
From an operational perspective, this vulnerability presents a significant threat to Android device security and integrity. The local privilege escalation capability means that an attacker with minimal privileges could potentially gain system-level access to execute arbitrary code with kernel-level privileges. This could enable complete system compromise, allowing attackers to bypass security controls, install malicious applications, or extract sensitive data from the device. The vulnerability's impact extends beyond individual device security to potentially affect entire Android ecosystems, particularly given the widespread adoption of Android-based devices across various manufacturers and security implementations.
The mitigation strategies for CVE-2022-20571 should focus on immediate patch deployment from upstream kernel maintainers, as referenced in the vulnerability description. Organizations should implement comprehensive monitoring for exploitation attempts and ensure all Android devices receive timely security updates. The vulnerability aligns with CWE-416, which addresses use-after-free conditions, and maps to ATT&CK technique T1068, which covers local privilege escalation. Device manufacturers should conduct thorough security assessments of their kernel implementations and consider implementing additional runtime protections such as kernel address space layout randomization and stack canaries to reduce the exploitability of similar memory corruption vulnerabilities.