CVE-2025-4804 in Fireware OS
Summary
by MITRE • 05/17/2025
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS allows Stored XSS via the spamBlocker module. This vulnerability requires an authenticated administrator session to a locally managed Firebox. This issue affects Fireware OS: from 12.0 through 12.11.1.
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Analysis
by VulDB Data Team • 05/17/2025
The vulnerability identified as CVE-2025-4804 represents a critical security flaw in WatchGuard Fireware OS that falls under the category of improper input neutralization during web page generation. This weakness manifests as a stored cross-site scripting vulnerability within the spamBlocker module, which is a core component of the firewall's email security functionality. The vulnerability specifically affects versions of Fireware OS ranging from 12.0 through 12.11.1, indicating a broad impact across multiple releases of the platform's security infrastructure. The stored nature of this XSS vulnerability means that malicious payloads can be permanently injected into the web application's database and subsequently executed whenever legitimate users access affected pages, making this particularly dangerous for administrative interfaces.
The technical exploitation of this vulnerability requires an authenticated administrator session to a locally managed Firebox, which establishes a clear attack vector that involves gaining administrative privileges within the organization's network security infrastructure. This prerequisite significantly impacts the attack surface, as it requires an adversary to first compromise administrative credentials or gain physical access to the device. The spamBlocker module serves as the attack entry point where malicious input can be injected through web forms or configuration parameters that are not properly sanitized before being rendered in web pages. This flaw directly relates to CWE-79, which defines cross-site scripting as the failure to properly neutralize user input data before it is incorporated into dynamically generated web content.
The operational impact of this vulnerability extends beyond simple data theft or session hijacking, as it provides attackers with the ability to execute arbitrary code within the context of the administrator's session. This capability enables adversaries to potentially escalate privileges, modify firewall configurations, access sensitive network data, and establish persistent backdoors within the organization's security infrastructure. The stored nature of the vulnerability means that once exploited, the malicious code remains active until manually removed from the system, creating a long-term security risk. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, and potentially T1566 for phishing attacks that could leverage the compromised administrative interface to further compromise network security. The vulnerability's impact on email security functionality specifically targets the spamBlocker module, which is critical for protecting organizations from malicious email traffic and phishing attempts.
Organizations affected by CVE-2025-4804 should immediately implement mitigation strategies that include applying the latest security patches from WatchGuard, which would address the input validation issues within the spamBlocker module. Network segmentation and access controls should be strengthened to limit the scope of potential exploitation, while monitoring systems should be enhanced to detect anomalous behavior in administrative sessions. Regular security audits of firewall configurations and user access privileges should be conducted to identify potential compromise indicators. Additionally, implementing multi-factor authentication for administrative access and establishing strict change management procedures for firewall configurations can significantly reduce the risk of exploitation. The vulnerability demonstrates the importance of input validation in web applications and highlights how even administrative interfaces can be compromised when proper sanitization measures are not implemented, making this a critical issue for network security teams to address immediately.