CVE-2023-4980 in librenms
Summary
by MITRE • 09/15/2023
Cross-site Scripting (XSS) - Generic in GitHub repository librenms/librenms prior to 23.9.0.
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Analysis
by VulDB Data Team • 05/08/2026
Cross-site scripting vulnerabilities represent one of the most prevalent and dangerous web application security flaws, allowing attackers to inject malicious scripts into web pages viewed by other users. The specific vulnerability identified in the librenms/librenms repository affects versions prior to 23.9.0 and falls under the generic category of XSS flaws that can potentially compromise user sessions and data integrity. This vulnerability enables attackers to execute arbitrary JavaScript code within the context of a victim's browser, creating a significant threat vector for web applications that process user input without proper sanitization or validation.
The technical implementation of this XSS vulnerability stems from insufficient input validation and output encoding mechanisms within the LibreNMS application codebase. When users interact with the web interface and provide input through various forms, search parameters, or URL parameters, the application fails to adequately sanitize this data before rendering it back to the user interface. This lack of proper input sanitization creates an environment where malicious actors can embed script tags or other executable code within user-supplied content, which then executes in the browser context of legitimate users who view the affected pages. The vulnerability manifests when the application displays user-controllable data without appropriate HTML escaping or context-appropriate encoding, allowing script execution to occur in the victim's browser session.
The operational impact of this vulnerability extends beyond simple script execution, as it can lead to session hijacking, credential theft, and unauthorized administrative actions within the LibreNMS environment. Attackers can leverage this flaw to steal session cookies, impersonate legitimate users, and potentially gain elevated privileges within the network monitoring system. The consequences are particularly severe given that LibreNMS is commonly deployed in enterprise environments for critical network infrastructure monitoring, where unauthorized access could result in complete compromise of network visibility and security controls. The vulnerability affects all users interacting with the web interface, including administrators who may be tricked into executing malicious scripts through phishing attacks or compromised pages, making the attack surface particularly broad.
Mitigation strategies for this XSS vulnerability require comprehensive input validation and output encoding mechanisms throughout the application codebase. The recommended approach involves implementing strict input sanitization routines that filter or escape potentially dangerous characters and patterns before processing user data, combined with proper output encoding based on the context where data is rendered. Security practitioners should implement Content Security Policy headers to limit script execution sources and employ proper HTML escaping for all user-controllable data displayed in web interfaces. Additionally, regular security code reviews and automated vulnerability scanning should be integrated into the development lifecycle to identify and remediate similar issues before they can be exploited. This vulnerability aligns with CWE-79 which specifically addresses Cross-site Scripting flaws and represents a fundamental security weakness that requires systematic remediation across the entire application architecture. The ATT&CK framework categorizes this as a technique for "Command and Control" and "Credential Access" through web-based exploitation, making it a critical component in the overall threat landscape for network monitoring systems. Organizations should immediately upgrade to version 23.9.0 or later where the vulnerability has been addressed through proper input validation and sanitization mechanisms.