CVE-2023-21118 in Android
Summary
by MITRE • 05/16/2023
In unflattenString8 of Sensor.cpp, there is a possible out of bounds read due to a heap buffer overflow. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11 Android-12 Android-12L Android-13Android ID: A-269014004
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability identified as CVE-2023-21118 represents a critical heap buffer overflow condition within the Android sensor subsystem, specifically in the unflattenString8 function located in Sensor.cpp. This flaw exists in the Android operating system versions 11, 12, 12L, and 13, making it a widespread concern across multiple Android releases. The vulnerability stems from inadequate bounds checking during the processing of sensor data structures, particularly when handling string data within sensor communication protocols. The heap buffer overflow occurs when the system attempts to read beyond the allocated memory boundaries while parsing sensor information, creating a scenario where adjacent memory regions can be accessed without proper validation.
The technical nature of this vulnerability places it under CWE-125, which specifically addresses out-of-bounds read conditions in software systems. This type of vulnerability allows an attacker to potentially access sensitive information stored in adjacent memory locations, which may contain credentials, application data, or system configuration details. The exploitation of this flaw requires no user interaction and can be accomplished through local processes that utilize the sensor framework, making it particularly dangerous as it can be triggered automatically during normal device operation. The vulnerability does not require elevated privileges or additional execution capabilities, which significantly broadens its attack surface and makes it accessible to any local process with sensor access permissions.
From an operational impact perspective, this vulnerability creates a significant risk for information disclosure attacks within Android devices. The local information disclosure threat means that malicious applications or processes running on the same device could potentially extract sensitive data from memory locations adjacent to the vulnerable buffer. This could include user credentials, personal information, application data, or even system-level configuration details that might be stored in nearby memory segments. The vulnerability's presence in core sensor processing components means that legitimate sensor operations could be exploited to harvest confidential information, potentially leading to privacy breaches or further compromise of device security.
The mitigation strategies for this vulnerability should focus on implementing proper bounds checking mechanisms within the sensor framework, specifically in the unflattenString8 function where the heap buffer overflow occurs. Android security patches should include enhanced memory validation routines that prevent reading beyond allocated buffer boundaries. System administrators and device manufacturers should prioritize immediate deployment of security updates that address this specific memory corruption issue. Additionally, runtime protections such as address space layout randomization and stack canaries should be strengthened to provide additional layers of defense against similar buffer overflow conditions. The vulnerability's classification under the ATT&CK framework would place it within the information gathering and privilege escalation categories, emphasizing the need for comprehensive security hardening measures across the Android platform.