CVE-2025-70521 in x7a Firmware
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 administrators or users to test network connectivity by sending ICMP echo requests to specified targets. However, the implementation fails to properly sanitize or validate user-supplied input before passing it to underlying system commands. In many embedded VoIP devices and Android-based appliances, such utilities often invoke shell interpreters like /bin/sh or direct command-line tools without adequate filtering mechanisms. This architectural oversight creates a pathway for Remote Code Execution (RCE), allowing an attacker who can access the management interface to execute arbitrary operating system commands with the privileges of the application process.
From a technical perspective, this flaw is classified under CWE-78, which denotes Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. The vulnerability arises because the ping tool likely concatenates user input directly into a command string without escaping special characters such as semicolons, ampersands, or pipe symbols. An unauthenticated attacker can exploit this by crafting a malicious payload that terminates the intended ping operation and appends additional commands. For instance, an attacker might inject a sequence like ; cat /etc/passwd to read sensitive system files, thereby bypassing the intended functionality of the tool entirely. Since the underlying operating system is Android, successful exploitation grants access to the Linux kernel environment running on the device, which often hosts services with elevated privileges or access to local network resources that are not directly exposed to external networks.
The operational impact of this vulnerability is severe due to its unauthenticated nature and the potential for full system compromise. Because no authentication is required to trigger the exploit, any entity capable of reaching the management portal's IP address can initiate the attack. This significantly lowers the barrier to entry for malicious actors compared to vulnerabilities that require valid credentials. Once code execution is achieved on the Android OS layer, an attacker can pivot further into the internal network where the VoIP phone resides. They may intercept sensitive voice communications, manipulate call routing configurations, or use the device as a foothold for lateral movement within the corporate infrastructure. Additionally, since these devices often handle real-time communication data, compromising them poses significant risks to confidentiality and integrity of business operations.
This vulnerability aligns with several techniques in the MITRE ATT&CK framework, particularly T1059 Command and Scripting Interpreter, which covers the use of shell commands for execution. It also relates to T1190 Exploit Public-Facing Application, as the management portal is typically accessible over network boundaries or internal subnets where unauthorized access might be attempted. The lack of input validation reflects a failure in secure coding practices that are critical for embedded systems handling administrative functions.
To mitigate this risk, immediate action should be taken to update the Fanvil x7a firmware to a patched version released by the vendor after 2.6.0.1182, which addresses the input sanitization issues within the diagnostic tools. If an updated firmware is not immediately available, network-level controls such as firewall rules restricting access to the management portal should be implemented to limit exposure only to trusted administrative IP ranges. Additionally, disabling unused services and features on the device can reduce the attack surface. Long-term remediation involves enforcing strict input validation patterns in all user-facing components of embedded systems and adopting secure development lifecycle practices that include static analysis for command injection vulnerabilities during software design phases.