CVE-2025-10546 is a medium-severity vulnerability classified under CWE-79, indicating improper neutralization of input during web page generation, commonly known as Cross-Site Scripting (XSS). This vulnerability affects the PPC XPON ONT (Optical Network Terminal) 2K15X devices manufactured by PPC Technologies, specifically versions v2.3.15PPCL and v1.0.3. The root cause lies in the inadequate input validation of Common Gateway Interface (CGI) parameters on the device's web management portal. An attacker can exploit this flaw remotely by injecting malicious JavaScript code into vulnerable CGI parameters. When a legitimate user accesses the affected web interface, the injected script executes in their browser context, potentially leading to session hijacking, credential theft, or unauthorized actions performed with the user's privileges. The vulnerability is reflected XSS, meaning the malicious payload is not stored persistently but reflected immediately in the HTTP response. The CVSS 4.0 base score is 5.1, indicating a medium severity level. The vector string (AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N) shows that the attack is network-based, requires no privileges or authentication, but does require user interaction (e.g., clicking a crafted link). The impact on confidentiality and integrity is low to limited, with no direct availability impact. No known exploits are currently reported in the wild, and no patches have been linked yet. However, the vulnerability poses a risk to the security of network management interfaces, which are critical for device configuration and monitoring.

For European organizations, this vulnerability could compromise the security of network infrastructure managed via PPC XPON ONT 2K15X devices. These Optical Network Terminals are typically used by ISPs and enterprises for fiber-optic broadband connectivity. Exploitation could allow attackers to execute malicious scripts in the context of network administrators or users accessing the device's web portal, potentially leading to theft of credentials, session hijacking, or manipulation of device settings. This could result in unauthorized network access, interception of sensitive data, or disruption of network services. Although the vulnerability is medium severity and requires user interaction, the strategic importance of network infrastructure in sectors such as telecommunications, finance, and critical infrastructure in Europe elevates the risk. Additionally, the reflected XSS could be used as a stepping stone in multi-stage attacks targeting broader network compromise. The lack of authentication requirement for exploitation increases the attack surface, especially if the management interface is exposed or accessible from less secure network segments.

European organizations should implement the following specific mitigations: 1) Restrict access to the PPC XPON ONT web management portal by network segmentation and firewall rules, allowing only trusted administrative hosts to connect. 2) Employ web application firewalls (WAFs) with custom rules to detect and block suspicious CGI parameter inputs indicative of XSS payloads. 3) Educate network administrators to avoid clicking on untrusted links or opening suspicious emails that could trigger the reflected XSS attack. 4) Monitor network device logs and web portal access patterns for anomalies that may indicate exploitation attempts. 5) Coordinate with PPC Technologies for timely updates or patches and apply them promptly once available. 6) If possible, disable or limit the use of CGI parameters that are vulnerable or replace the web management interface with more secure alternatives. 7) Implement Content Security Policy (CSP) headers on the device’s web interface to restrict script execution origins, mitigating the impact of injected scripts. 8) Regularly audit and test the security of network management interfaces to identify and remediate similar vulnerabilities proactively.