CVE-2023-21075 in Android
Summary
by MITRE • 03/24/2023
In get_svc_hash of nan.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-261857862References: N/A
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Analysis
by VulDB Data Team • 09/10/2025
The vulnerability identified as CVE-2023-21075 resides within the nan.cpp file in the Android kernel's get_svc_hash function, presenting a critical heap buffer overflow condition that can result in local privilege escalation. This flaw manifests as an out-of-bounds write operation, where the system attempts to write data beyond the allocated memory boundaries of a heap buffer. The vulnerability specifically impacts Android kernel implementations and is tracked under Android ID A-261857862, indicating its severity and the need for immediate attention from device manufacturers and security teams.
The technical implementation of this vulnerability stems from improper bounds checking within the get_svc_hash function, which processes service hash calculations for nan (nanotechnology) related operations. When the function handles memory allocation for service hash storage, it fails to validate the size of data being written against the allocated buffer boundaries. This allows an attacker to potentially overwrite adjacent memory locations with malicious data, creating opportunities for arbitrary code execution. The heap buffer overflow occurs during the processing of service hash calculations, where the system does not properly verify that the input data fits within the allocated memory space.
The operational impact of this vulnerability extends beyond simple memory corruption, as it enables local privilege escalation to system-level execution privileges without requiring user interaction for exploitation. This means that any local attacker with access to the device can leverage this vulnerability to gain elevated privileges and potentially access sensitive system resources. The attack vector is particularly concerning because it does not require user interaction, making it an automatic privilege escalation vulnerability that can be exploited silently in the background. The vulnerability's potential for system-level execution privileges makes it a prime target for attackers seeking to establish persistent access or extract confidential information from affected devices.
Mitigation strategies for CVE-2023-21075 should prioritize immediate patch deployment from Android vendors, as this vulnerability represents a critical security risk. System administrators and device manufacturers should implement the latest kernel updates that address the heap buffer overflow in the get_svc_hash function. Additionally, memory safety improvements should include enhanced bounds checking mechanisms, proper input validation for service hash calculations, and comprehensive memory allocation verification. The vulnerability aligns with CWE-121 heap-based buffer overflow and can be categorized under ATT&CK technique T1068 for local privilege escalation, emphasizing the need for robust memory management practices. Organizations should also implement runtime protections such as stack canaries, address space layout randomization, and memory corruption detection mechanisms to reduce the attack surface. Regular security audits of kernel components and implementation of automated vulnerability scanning tools will help identify similar issues before they can be exploited by malicious actors.