CVE-2023-21056 in Android
Summary
by MITRE • 03/24/2023
In lwis_slc_buffer_free of lwis_device_slc.c, there is a possible memory corruption due to type confusion. 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-245300559References: N/A
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Analysis
by VulDB Data Team • 09/10/2025
The vulnerability identified as CVE-2023-21056 resides within the Android kernel's lwis device driver implementation, specifically in the lwis_slc_buffer_free function located in lwis_device_slc.c. This flaw represents a type confusion vulnerability that arises from improper handling of memory buffer management within the kernel space. The issue manifests when the system attempts to free memory buffers associated with the lwis device, creating a scenario where the kernel's memory management logic incorrectly interprets the type of data structures being processed. Such type confusion vulnerabilities are particularly dangerous in kernel contexts where memory corruption can lead to arbitrary code execution and privilege escalation. The vulnerability is classified under CWE-843, which specifically addresses type confusion issues where a program uses a variable of one data type in a context expecting another data type, leading to unpredictable behavior and potential security breaches.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates a pathway for local privilege escalation attacks. An attacker with low-privilege access to a device running affected Android kernel versions could exploit this flaw to gain system-level execution privileges without requiring user interaction or physical access to the device. This makes the vulnerability particularly concerning for mobile devices where users may have varying levels of system access. The attack vector leverages kernel memory management functions that are typically invoked during normal device operation, making exploitation more likely and harder to detect. The vulnerability's presence in the lwis device driver suggests it may be related to specific hardware or device functionality, potentially affecting devices that utilize this particular driver for system communication or data processing tasks.
The exploitation of CVE-2023-21056 aligns with ATT&CK technique T1068, which describes the use of local privilege escalation techniques to gain system-level access. This vulnerability fits within the broader category of kernel exploits that leverage memory corruption flaws to bypass security protections. The fact that this vulnerability requires system execution privileges for exploitation indicates it operates at a kernel level where the attacker must already have some degree of system access. However, the potential for privilege escalation means that even limited access could be sufficient to trigger the vulnerability and achieve full system compromise. The Android kernel's memory management subsystem, which handles buffer allocation and deallocation for device drivers, becomes a critical attack surface where this type confusion vulnerability can be leveraged to execute malicious code with elevated privileges.
Mitigation strategies for CVE-2023-21056 should focus on kernel-level patches and memory management improvements that address the specific type confusion issue in the lwis device driver. Android security updates typically address such vulnerabilities through kernel patches that correct the buffer management logic and implement proper type checking mechanisms. Organizations should prioritize applying the latest security patches from Google and device manufacturers, as these updates contain fixes for the memory corruption issue. Additional defensive measures include kernel memory protection features such as stack canaries, memory randomization, and enhanced kernel address space layout randomization. Device administrators should also monitor for unusual system behavior or unauthorized privilege escalation attempts that might indicate exploitation attempts. The vulnerability's classification as a local privilege escalation means that traditional network-based security measures may not prevent exploitation, requiring more comprehensive system-level protections and access controls to mitigate the risk effectively.