CVE-2026-3343 in Fireware OS
Summary
by MITRE • 03/03/2026
A reflected cross-site scripting (XSS) vulnerability in the Fireware OS Web UI enabled execution of malicious JavaScript in the context of an authenticated management user's browser when they click on a specially crafted link.
This vulnerability affects Fireware OS 12.7 up to and including 12.11.7 and 2025.1 up to and including 2026.1.1.
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Analysis
by VulDB Data Team • 03/06/2026
This reflected cross-site scripting vulnerability represents a critical security flaw in the Fireware OS web management interface that enables attackers to execute malicious JavaScript code within the browser context of authenticated administrators. The vulnerability stems from improper input validation and output encoding within the web user interface components that handle user-supplied data. When an authenticated user clicks on a maliciously crafted link containing crafted script payloads, the web application fails to properly sanitize the input before rendering it in the browser, creating an XSS vector that can be exploited to compromise the administrative session.
The technical implementation of this vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications. The reflected nature of this vulnerability means that the malicious script is reflected back from the web server to the user's browser without being stored on the server, making it particularly dangerous as it requires no persistent storage of malicious content. The vulnerability affects a broad range of Fireware OS versions including the 12.7 through 12.11.7 release series and the 2025.1 through 2026.1.1 release series, indicating this is likely a widespread issue affecting multiple major product lines within the Fireware OS ecosystem.
The operational impact of this vulnerability is severe as it provides attackers with the ability to execute arbitrary JavaScript code within the context of an authenticated administrator's browser session. This could enable attackers to steal session cookies, perform administrative actions on behalf of the user, access sensitive configuration data, or redirect users to malicious sites. The authentication context is crucial here as it means that the attack requires only a single click from an authenticated user rather than needing to establish initial access through other means. According to ATT&CK framework technique T1566.001, this represents a social engineering attack vector that leverages the trust relationship between the user and the system. The vulnerability's exploitation could lead to complete system compromise, as administrative privileges would be available to the attacker.
Mitigation strategies should include immediate implementation of input validation and output encoding controls within the web application to prevent the reflection of untrusted data. Organizations should deploy web application firewalls to detect and block malicious payloads, implement content security policies to restrict script execution, and conduct thorough security testing of web interfaces. Additionally, users should be educated about the dangers of clicking untrusted links, and administrators should be advised to avoid clicking suspicious links even when they appear to come from legitimate sources. The affected versions should be updated to patched releases as soon as possible, with security teams monitoring for any exploitation attempts and implementing network-level protections to detect and block malicious traffic patterns associated with exploitation attempts.