CVE-2025-66258: Critical XSS Flaw Imperils DB Elettronica Mozart FM Transmitters

Overview

CVE-2025-66258 describes a Stored Cross-Site Scripting (XSS) vulnerability affecting DB Electronica Telecomunicazioni S.p.A. Mozart FM Transmitters. Specifically, versions 30, 50, 100, 300, 500, 1000, 2000, 3000, 3500, 6000, 7000 are susceptible. This vulnerability allows an attacker to inject malicious JavaScript code into the system, potentially leading to unauthorized actions, data theft, or service disruption.

Technical Details

The vulnerability stems from improper handling of filenames within the patchlist.xml file. User-controlled filenames are directly concatenated into this XML file without adequate encoding or sanitization. An attacker can exploit this by crafting filenames containing malicious JavaScript payloads (e.g., <img src=x onerror=alert()>.bin). When ajax.js processes and renders the patchlist.xml file, the injected JavaScript code is executed within the context of the application, leading to a Stored XSS attack.

The root cause is the lack of proper input validation and output encoding when handling filenames. Specifically, the system fails to escape or sanitize special characters that have meaning in XML, allowing the injection of arbitrary XML elements containing JavaScript.

CVSS Analysis

Currently, the CVSS score and severity level for CVE-2025-66258 are marked as N/A. However, based on the nature of the vulnerability (Stored XSS) and the potential impact, a high severity rating is likely. A successful XSS attack can lead to:

• Account compromise
• Session hijacking
• Redirection to malicious websites
• Defacement of the web interface
• Potentially, remote code execution if the affected system is poorly configured or has additional vulnerabilities.

Possible Impact

The successful exploitation of this vulnerability could have significant consequences for organizations using affected Mozart FM Transmitters. An attacker could potentially:

• Disrupt FM broadcast services.
• Compromise sensitive configuration data stored on the transmitter.
• Use the compromised transmitter as a launchpad for further attacks on the network.
• Damage the reputation of the broadcasting organization.

Mitigation and Patch Steps

To mitigate the risk associated with CVE-2025-66258, the following steps are recommended:

1. Apply the official patch: Contact DB Electronica Telecomunicazioni S.p.A. to obtain and apply the official patch for your specific Mozart FM Transmitter model. This is the most effective solution.
2. Input Validation: Implement robust input validation and sanitization on all user-supplied data, including filenames. Ensure that special characters are properly encoded before being stored in the patchlist.xml file.
3. Output Encoding: Encode all data retrieved from the patchlist.xml file before rendering it in the web interface. Use appropriate encoding functions to prevent the execution of malicious JavaScript code.
4. Web Application Firewall (WAF): Consider deploying a Web Application Firewall (WAF) to detect and block XSS attacks.
5. Regular Security Audits: Conduct regular security audits and penetration testing to identify and address potential vulnerabilities in your systems.

References

• Abdulmhsblog.com – WebFMVulns