CVE-2023-21147 in Android
Summary
by MITRE • 06/28/2023
In lwis_i2c_device_disable of lwis_device_i2c.c, there is a possible UAF due to a logic error in the code. 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-269661912References: N/A
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability identified as CVE-2023-21147 represents a critical use-after-free condition within the Android kernel's I2C device management subsystem. This flaw exists in the lwis_i2c_device_disable function located in the lwis_device_i2c.c source file, where a logic error creates a window of opportunity for malicious exploitation. The vulnerability specifically affects the lwis (Linux Wireless Interface) I2C device driver implementation that manages I2C communication interfaces within Android devices. The underlying issue stems from improper memory management where the function fails to properly handle reference counting or synchronization mechanisms when disabling I2C devices, creating a scenario where freed memory objects may still be accessed by subsequent operations.
The technical nature of this vulnerability aligns with CWE-416, which categorizes use-after-free conditions as a fundamental memory safety issue. The flaw manifests when the lwis_i2c_device_disable function processes device shutdown operations without ensuring proper synchronization or reference validation before releasing memory resources. This logic error creates a race condition where multiple code paths might attempt to access the same memory location after it has been freed, potentially allowing an attacker to manipulate the freed memory contents or redirect execution flow. The vulnerability's classification as a local privilege escalation means that an attacker with minimal privileges can leverage this flaw to gain elevated system access without requiring additional execution privileges or user interaction for exploitation.
The operational impact of CVE-2023-21147 extends beyond simple memory corruption, as it provides a pathway for attackers to achieve system-level privileges on affected Android devices. This vulnerability affects the Android kernel version and is particularly concerning because it requires no user interaction for exploitation, making it a significant security risk for mobile devices. The flaw's presence in the lwis device I2C subsystem means that any application or service that interacts with I2C devices could potentially trigger the vulnerability, creating a broad attack surface. The Android ID A-269661912 indicates this was properly tracked within Google's security infrastructure, highlighting the severity and widespread potential impact across various Android device models and versions.
Mitigation strategies for CVE-2023-21147 should focus on immediate kernel updates that address the memory management logic error in the lwis_i2c_device_disable function. Security researchers should implement proper synchronization mechanisms and reference counting to prevent the premature release of memory resources during device disable operations. The fix should ensure that all device references are properly validated before memory deallocation occurs, preventing the use-after-free condition. Additionally, system administrators should monitor for any suspicious behavior related to I2C device management and consider implementing runtime protections such as stack canaries or memory sanitization tools. Organizations should also review their Android device management policies to ensure timely deployment of security patches and maintain awareness of related vulnerabilities in the lwis subsystem that may present similar exploitation vectors. The vulnerability's characteristics align with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' and demonstrates how kernel-level flaws can be leveraged for system compromise without requiring user interaction.