CVE-2020-15878 in LibreNMS
Summary
by MITRE • 08/26/2026
An issue was discovered in LibreNMS 1.65. A remote authenticated attacker with normal privileges can extract all the information from the LibreNMS database via a SQL injection in the address parameter in the /ajax_table.php API endpoint.
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified in LibreNMS version 1.65 represents a significant security flaw within its web-based network monitoring interface, specifically affecting the AJAX table rendering functionality. This issue is classified as an SQL Injection (SQLi) vulnerability located within the address parameter of the /ajax_table.php API endpoint. Unlike many high-severity vulnerabilities that require administrative privileges or unauthenticated access to exploit, this particular weakness allows exploitation by a remote authenticated attacker operating with normal user privileges. The existence of such a flaw in a system designed for network observability underscores the critical importance of input validation and secure coding practices even within internal-facing applications where trust boundaries are often assumed to be tighter than those on public internet services.
From a technical perspective, the root cause lies in the insufficient sanitization or parameterized query implementation when processing user-supplied data passed via the address parameter. When an authenticated user submits a request to /ajax_table.php with maliciously crafted input containing SQL syntax, the backend application fails to properly distinguish between executable code and data. Consequently, the database engine interprets these injected commands as part of the original SQL statement. This allows the attacker to manipulate the query structure, potentially bypassing intended logic or extracting arbitrary data from the underlying relational database management system that stores network topology, device configurations, performance metrics, and user credentials associated with LibreNMS operations.
The operational impact of this vulnerability is severe due to the comprehensive nature of information stored within a Network Management System like LibreNMS. An attacker can extract all information contained in the LibreNMS database, which typically includes sensitive details about network infrastructure such as IP addresses, device types, SNMP community strings, interface statistics, and potentially user account data including hashed passwords or session tokens. This level of access effectively compromises the confidentiality integrity of the monitoring platform itself. Furthermore, because LibreNMS often serves as a central hub for observing critical IT assets, compromising its database can provide an attacker with valuable intelligence to plan further attacks against other systems within the network perimeter, leveraging knowledge of device vulnerabilities and operational schedules derived from the extracted data.
In terms of industry standard classifications, this vulnerability aligns closely with CWE-89 Improper Neutralization of Special Elements used in an SQL Command commonly known as SQL Injection. The attack vector is categorized under ATT&CK technique T1059 Command and Scripting Interpreter if the injection leads to command execution, but more directly it falls under data exfiltration patterns associated with unauthorized access to sensitive information. The privilege requirement places this within the context of a lower-privilege user escalating their impact through application logic flaws rather than system-level exploits, highlighting risks in role-based access control implementations where API endpoints may not enforce strict parameter constraints based on user roles.
Mitigation strategies must focus primarily on immediate patching and long-term secure development practices. Administrators should upgrade LibreNMS to the latest stable version as soon as possible, ensuring that vendor-provided fixes for this specific SQL injection vector are applied. In environments where upgrading is not immediately feasible, temporary mitigations include implementing a Web Application Firewall (WAF) with rules specifically tuned to detect and block common SQL injection payloads targeting the /ajax_table.php endpoint. Additionally, reviewing application code to ensure all database queries utilize prepared statements or parameterized queries rather than string concatenation for building SQL commands is essential. Regular security audits and static analysis of PHP codebases can help identify similar vulnerabilities in other API endpoints before they are exploited by malicious actors seeking to compromise network monitoring infrastructure.