CVE-2025-70518 in Fanvil
Summary
by MITRE • 10/07/2026
The management portal's diagnostic ping tool of Fanvil x7a firmware version 2.6.0.1182 does not handle user supplied input securely. The lack of secure user input handling allows any unauthenticated attacker to inject commands and run code in the underlying Android operating system.
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified in the Fanvil x7a firmware version 2.6.0.1182 represents a critical security flaw within the device's management portal, specifically affecting the diagnostic ping utility. This component is designed to allow network administrators to test connectivity by sending ICMP echo requests to specified target addresses. However, the implementation fails to properly sanitize or validate user-supplied input before passing it to underlying system commands. This lack of secure input handling creates a direct pathway for command injection attacks, allowing malicious actors to execute arbitrary operating system commands with the privileges associated with the web service process.
From a technical perspective, this flaw aligns closely with CWE-78, which describes Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. The vulnerability arises because the application constructs shell commands using unsanitized user input without employing proper escaping mechanisms or parameterized execution methods. In many embedded VoIP devices running Android-based firmware, such utilities often invoke system shells like /bin/sh or busybox ash to perform network diagnostics. When an attacker provides a payload containing special characters such as semicolons, ampersands, or pipe symbols, these are interpreted by the shell rather than treated as literal data for the ping command. This allows the injection of additional commands that execute sequentially or conditionally based on the success of the initial ping operation.
The operational impact of this vulnerability is severe due to its unauthenticated nature. An attacker does not need valid credentials to exploit this flaw, meaning any individual with network access to the management interface can initiate an attack. By leveraging command injection, a threat actor can achieve Remote Code Execution on the underlying Android operating system. This level of compromise enables the attacker to perform actions such as reading sensitive configuration files, exfiltrating call logs and customer data stored locally, installing persistent backdoors for long-term access, or pivoting to other devices within the internal network segment where the VoIP phone resides. Given that these devices often handle voice communications containing potentially confidential information, this vulnerability poses significant risks to both organizational security posture and regulatory compliance regarding data privacy.
This type of exploitation is consistent with techniques observed in the MITRE ATT&CK framework under T1059 Command and Scripting Interpreter, specifically sub-techniques involving Unix Shell commands like sh or bash. Attackers frequently utilize such vulnerabilities during initial access phases to establish a foothold within an enterprise network. The ability to run code as root or with elevated privileges on the Android system further amplifies the danger, potentially allowing full control over the device's functionality and security controls.
Mitigation strategies for this vulnerability must prioritize immediate remediation through firmware updates provided by Fanvil that address the input validation logic in the diagnostic tool. If an update is not immediately available, network segmentation should be enforced to restrict access to the management portal only from trusted administrative subnets using firewalls or VLAN isolation. Additionally, disabling unused services and features on the VoIP phones can reduce the attack surface. Security monitoring solutions should also be configured to detect anomalous traffic patterns associated with command injection attempts targeting embedded device interfaces. Long-term development practices must enforce secure coding standards that mandate strict input validation and parameterized execution for all system-level interactions within firmware applications.