CVE-2022-20009 in Android
Summary
by MITRE • 05/11/2022
In various functions of the USB gadget subsystem, 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 kernelAndroid ID: A-213172319References: Upstream kernel
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Analysis
by VulDB Data Team • 05/13/2022
The vulnerability identified as CVE-2022-20009 represents a critical out-of-bounds write flaw within the Android kernel's USB gadget subsystem. This issue manifests in multiple functions where essential bounds checking mechanisms are absent, creating a pathway for malicious code to exploit memory corruption vulnerabilities. The USB gadget subsystem serves as a critical component in Android devices, managing communication between the device and external USB peripherals, making this vulnerability particularly dangerous as it operates at the kernel level where privileged operations occur. The flaw specifically affects the Android kernel implementation and was tracked under Android ID A-213172319, with upstream kernel references indicating this is a well-documented issue within the broader Linux kernel ecosystem.
The technical nature of this vulnerability stems from inadequate input validation within the USB gadget subsystem functions, where data structures are written beyond their allocated memory boundaries. This type of flaw falls under CWE-787, which specifically addresses out-of-bounds write vulnerabilities that can result in arbitrary code execution or privilege escalation. When an attacker can manipulate the USB gadget subsystem to trigger this condition, the kernel's memory layout becomes corrupted, potentially allowing for local privilege escalation without requiring any additional execution privileges or user interaction. The absence of bounds checking means that malicious inputs can cause memory corruption that may be exploited to gain higher privileges than initially granted to the running process.
The operational impact of CVE-2022-20009 extends beyond simple memory corruption, as it provides a direct path for local privilege escalation within Android devices. This means that any process running with standard user privileges could potentially leverage this vulnerability to execute code with kernel-level privileges, effectively bypassing Android's security model and access controls. The lack of user interaction requirement makes this vulnerability particularly concerning as it can be exploited automatically without any human intervention, potentially allowing for automated attacks or exploitation in compromised environments. The vulnerability affects the Android kernel specifically, making it relevant to all Android devices that utilize kernel versions containing this flaw, potentially impacting millions of devices worldwide.
Mitigation strategies for this vulnerability should focus on immediate kernel updates and patches provided by Google and device manufacturers, as this represents an upstream kernel issue requiring coordinated fixes across the Android ecosystem. Security teams should implement monitoring for anomalous USB gadget subsystem behavior and establish robust patch management procedures to ensure timely deployment of security updates. The vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation,' as it enables local users to escalate privileges without requiring additional execution privileges or user interaction. Organizations should also consider implementing additional security controls such as kernel address space layout randomization and other memory protection mechanisms to reduce the exploitability of similar vulnerabilities. Regular security assessments of kernel components and USB subsystems should be conducted to identify and remediate similar out-of-bounds write vulnerabilities before they can be exploited in the wild.