CVE-2023-21157 in Android
Summary
by MITRE • 06/28/2023
In encode of wlandata.cpp, there is a possible out of bounds write due to a heap buffer overflow. 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-263783137References: N/A
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability identified as CVE-2023-21157 resides within the wlandata.cpp file of the Android kernel, specifically manifesting as a heap buffer overflow that can result in out-of-bounds write conditions. This flaw exists in the encode function where improper bounds checking allows malicious data to overwrite adjacent memory locations within heap allocated buffers. The vulnerability is particularly concerning as it can potentially enable local privilege escalation to system-level execution privileges without requiring any user interaction for exploitation. The Android ID A-263783137 tracks this specific issue within the Android security framework, indicating its classification as a critical kernel-level vulnerability affecting the wireless networking subsystem.
The technical implementation of this vulnerability stems from inadequate input validation within the wireless data encoding process. When processing wireless network data, the system fails to properly verify buffer boundaries before writing data to heap-allocated memory regions. This allows an attacker to craft malicious wireless network packets or manipulate wireless data structures in such a way that the write operations exceed the allocated buffer size. The heap-based nature of the vulnerability means that memory corruption occurs in dynamically allocated regions rather than on the stack, making exploitation more complex but potentially more persistent. The flaw represents a classic buffer overflow condition that can be leveraged to overwrite critical memory locations including function pointers, return addresses, or other control data structures.
From an operational impact perspective, this vulnerability presents a significant risk to Android devices as it enables local privilege escalation without user interaction, meaning any application running on the device could potentially exploit this flaw. The requirement for system execution privileges suggests that successful exploitation could grant full system-level control over the device, potentially allowing attackers to install malicious applications, access sensitive data, modify system files, or even disable security features. The wireless networking context implies that exploitation could occur through various means including malicious Wi-Fi networks, rogue access points, or even through compromised wireless network infrastructure. This vulnerability directly impacts the Android kernel's security model and could potentially affect millions of devices running vulnerable kernel versions.
Mitigation strategies for CVE-2023-21157 should focus on immediate patch deployment through Android security updates, as the vulnerability requires kernel-level fixes to properly address the buffer overflow conditions. System administrators should prioritize updating devices to versions that include the patched wlandata.cpp implementation with proper bounds checking mechanisms. Additionally, network administrators should implement monitoring solutions to detect anomalous wireless network traffic patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-121 Heap-based Buffer Overflow, which is categorized under the broader category of CWE-119 Improper Access to Memory Locations in the Common Weakness Enumeration system. From an ATT&CK framework perspective, this vulnerability maps to T1068 Exploitation for Privilege Escalation and T1059 Command and Scripting Interpreter, as exploitation would likely involve system-level command execution and privilege elevation techniques. Organizations should also consider implementing network segmentation and wireless access control measures to limit potential attack vectors while awaiting patch deployment.