CVE-2023-7312 in Fusion
Summary
by MITRE • 10/31/2025
Nagios Fusion versions prior to 4.2.0 contain a stored cross-site scripting (XSS) vulnerability when adding or configuring Email Settings. Unsanitized user input can be stored and later rendered in the administrative UI, causing JavaScript to execute in the browser of any user who views the affected page. An attacker who can add or modify SMTP/email settings or manipulate the sendmail configuration fields could persist a malicious payload that executes in the context of other users' browsers.
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Analysis
by VulDB Data Team • 11/08/2025
The vulnerability identified as CVE-2023-7312 represents a critical stored cross-site scripting flaw within Nagios Fusion versions earlier than 4.2.0, specifically affecting the email settings configuration functionality. This issue arises from inadequate input sanitization mechanisms when processing user-supplied data during the addition or modification of email settings within the administrative interface. The flaw allows attackers to inject malicious JavaScript code that gets permanently stored within the application's database or configuration files, creating a persistent threat vector that remains active until manually removed or the software is upgraded.
The technical exploitation of this vulnerability occurs through the manipulation of email configuration parameters, particularly SMTP server settings and sendmail configuration fields. When administrators or authorized users navigate to the affected administrative pages to view or manage email settings, the malicious JavaScript code embedded within the stored input is executed within their browser context. This stored payload execution represents a classic server-side vulnerability that transforms into a client-side attack vector, leveraging the trust relationship between the web application and its users. The vulnerability is categorized under CWE-79 as a failure to sanitize user input, specifically manifesting as a stored XSS attack that can compromise user sessions and execute arbitrary code within the browser environment.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it provides attackers with the capability to establish persistent footholds within the target environment through session hijacking, credential theft, or redirection to malicious sites. Any user with administrative privileges or access to email configuration settings can become a vector for exploitation, making this vulnerability particularly dangerous in multi-user environments where administrative access is shared among multiple personnel. The attack surface is further expanded by the fact that the malicious code executes automatically when users view the affected pages, requiring no additional user interaction beyond normal administrative tasks.
Security practitioners should implement immediate mitigations including the mandatory upgrade to Nagios Fusion version 4.2.0 or later, which contains the necessary input validation and sanitization patches. Organizations should also consider implementing additional defensive measures such as web application firewalls with XSS detection capabilities, regular security scanning of administrative interfaces, and monitoring for unauthorized configuration changes. The vulnerability aligns with ATT&CK technique T1566.001 for initial access through malicious email attachments and T1071.004 for application layer protocol usage, making it particularly relevant for organizations implementing comprehensive threat hunting strategies. Network segmentation and least privilege access controls should be enforced for email configuration interfaces to limit the potential impact of successful exploitation attempts.