CVE-2025-70522 in x7a Firmware
Summary
by MITRE • 10/07/2026
The request handler of Fanvil x7a firmware version 2.6.0.1182 does not enforce any cross-origin resource protection for any state-changing request performed against the applications. Due to the lack of protection, cross-origin boundary can be completely bypassed, allowing for Cross-Site Request Forgery Attacks against any endpoint.
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified in Fanvil x7a firmware version 2.6.0.1182 represents a critical failure in implementing secure web application practices, specifically concerning the handling of cross-origin requests. The core technical flaw lies within the request handler component, which processes state-changing operations without enforcing any form of Cross-Origin Resource Sharing (CORS) policies or origin validation mechanisms. In modern web architectures, browsers enforce same-origin policy by default to prevent malicious sites from reading sensitive data from other sites. However, when a server accepts requests that modify application state, such as changing settings, initiating calls, or modifying user profiles, it must explicitly validate the source of those requests to ensure they originate from trusted domains. The absence of this validation means the device treats all incoming HTTP requests with equal trust regardless of their origin header, effectively nullifying browser-based security controls designed to mitigate cross-site attacks.
This lack of enforcement allows for a complete bypass of cross-origin boundaries, creating an environment ripe for Cross-Site Request Forgery (CSRF) attacks. An attacker can craft malicious web pages or scripts that trick an authenticated user into performing unintended actions on the Fanvil x7a device while they are logged in and their session is active. Because the firmware does not verify whether the request originated from a legitimate source, any state-changing endpoint becomes accessible to external actors. This includes endpoints responsible for configuration changes, call routing adjustments, or administrative functions. The attacker does not need to bypass authentication directly; instead, they exploit the user's existing authenticated session by forcing their browser to send requests with valid cookies and headers to the vulnerable device.
The operational impact of this vulnerability is severe due to the nature of IP phone systems like the Fanvil x7a. These devices are often integrated into corporate communication infrastructures where trust boundaries may be loosely defined or automated processes rely on internal network assumptions that do not account for web-based attack vectors. An attacker could potentially redirect calls, alter voicemail settings, disable security features, or even use the device as a pivot point to access other parts of the local network if further vulnerabilities exist. In enterprise environments, this can lead to significant business disruption, unauthorized long-distance charges, eavesdropping on sensitive conversations through call manipulation, and a general erosion of trust in the communication infrastructure. The ability to perform these actions remotely without user interaction makes it particularly dangerous for devices that are frequently left unattended or managed via web interfaces by IT staff who may not be aware of such subtle browser-based exploits.
From a classification perspective, this vulnerability aligns with CWE-352, which describes Cross-Site Request Forgery (CSRF). The failure to implement anti-CSRF tokens or validate the Origin and Referer headers is a textbook example of this weakness. Furthermore, in the context of the MITRE ATT&CK framework, this flaw facilitates techniques related to Command and Control as well as Lateral Movement if the device serves as an entry point into broader network segments. Attackers can leverage CSRF to automate interactions with the web interface, effectively turning legitimate user sessions into tools for malicious activity without needing credentials or exploiting buffer overflows.
Mitigation strategies must focus on implementing robust server-side validation mechanisms immediately upon firmware updates or through manual configuration if patches are not yet available. Developers should enforce strict CORS policies by checking the Origin header against a whitelist of trusted domains before processing any state-changing request. Additionally, implementing anti-CSRF tokens that are unique per session and required for all POST requests is essential to prevent forgery. Input validation on all parameters received from external sources further reduces the attack surface. For administrators using affected firmware versions 2.6.0.1182, it is critical to update to a patched version as soon as one is released by Fanvil. In the interim, restricting access to the web management interface to trusted IP addresses only and disabling unnecessary services can reduce exposure. Regular security audits of VoIP infrastructure should include checks for proper implementation of HTTP security headers such as SameSite cookie attributes and Content-Security-Policy directives to provide defense-in-depth against browser-based attacks.