CVE-2023-47304 in Box Telephone Adapter VDV23
Summary
by MITRE • 12/05/2023
An issue was discovered in Vonage Box Telephone Adapter VDV23 version VDV21-3.2.11-0.5.1, allows local attackers to bypass UART authentication controls and read/write arbitrary values to the memory of the device.
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Analysis
by VulDB Data Team • 02/22/2026
The vulnerability identified as CVE-2023-47304 represents a critical security flaw in Vonage Box Telephone Adapter VDV23 firmware version VDV21-3.2.11-0.5.1 that exposes the device to local privilege escalation and memory manipulation attacks. This issue stems from insufficient authentication controls within the Universal Asynchronous Receiver-Transmitter (UART) interface, which serves as a critical communication pathway for device configuration and diagnostic functions. The flaw allows unauthorized local attackers to bypass established authentication mechanisms and gain direct access to the device's memory space, enabling them to read and write arbitrary data values that could compromise the entire system integrity.
The technical implementation of this vulnerability resides in the UART authentication controls that fail to properly validate access requests from local users. This weakness creates a direct pathway for privilege escalation attacks where an attacker with physical or local network access can manipulate memory addresses and execute unauthorized operations. The vulnerability is classified under CWE-284 Access Control Issues, specifically manifesting as inadequate access control mechanisms that permit unauthorized memory access. The device's firmware appears to lack proper authentication checks at the UART interface level, allowing local users to bypass standard security controls that should restrict access to sensitive memory regions.
From an operational perspective, this vulnerability presents significant risks to the security posture of telephony infrastructure deployments that rely on Vonage Box adapters. Local attackers who can access the device through physical presence or network proximity can potentially modify critical system parameters, inject malicious code, or extract sensitive information from the device memory. The impact extends beyond simple unauthorized access as attackers could manipulate device configuration settings, compromise communication channels, or establish persistent backdoors within the network infrastructure. This vulnerability directly affects the availability, integrity, and confidentiality of the telephony services provided by the adapter, potentially leading to service disruption or unauthorized surveillance.
The attack surface for this vulnerability is primarily limited to local access scenarios where an attacker has physical proximity to the device or network access to the same local network segment. However, the implications are severe as the attack requires minimal privileges and can result in complete system compromise. Security professionals should consider this vulnerability in the context of ATT&CK framework category T1068, which covers Local Privilege Escalation, and T1566, which addresses credential access through physical access. Organizations using affected Vonage Box models should implement immediate mitigations including firmware updates from Vonage, network segmentation to limit local access, and physical security controls to prevent unauthorized device access. The vulnerability underscores the critical importance of proper authentication controls in embedded systems and highlights the need for comprehensive security testing of communication interfaces in network infrastructure devices.