CVE-2020-15873 in LibreNMS
Summary
by MITRE
In LibreNMS before 1.65.1, an authenticated attacker can achieve SQL Injection via the customoid.inc.php device_id POST parameter to ajax_form.php.
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Analysis
by VulDB Data Team • 07/22/2020
The vulnerability CVE-2020-15873 represents a critical SQL injection flaw in LibreNMS versions prior to 1.65.1, specifically affecting the ajax_form.php endpoint through the customoid.inc.php device_id POST parameter. This vulnerability demonstrates a classic input validation failure where user-supplied data is directly incorporated into database queries without proper sanitization or parameterization. The flaw exists within the device management functionality of LibreNMS, which is a widely deployed network monitoring solution used by organizations to track network infrastructure components including routers, switches, and other network devices.
The technical implementation of this vulnerability stems from improper handling of the device_id parameter within the customoid.inc.php include file when processed by ajax_form.php. When an authenticated user submits a malicious device_id value through the POST request, the application fails to validate or escape the input before incorporating it into SQL queries. This creates an exploitable condition where an attacker can manipulate database queries to extract, modify, or delete sensitive information from the LibreNMS database. The vulnerability is classified as CWE-89 SQL Injection, which is one of the most prevalent and dangerous web application security flaws according to the CWE database.
The operational impact of this vulnerability is significant for organizations using affected LibreNMS versions, as it allows authenticated attackers to potentially gain unauthorized access to sensitive network monitoring data. An attacker could leverage this vulnerability to extract device configurations, user credentials, network topology information, and other confidential data stored within the LibreNMS database. The attack requires authentication, limiting the exposure to users who already have access to the system, but this still represents a privilege escalation risk for compromised accounts. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1078 Valid Accounts, as it exploits legitimate user credentials to perform unauthorized database operations.
The security implications extend beyond simple data theft, as this vulnerability could enable attackers to modify network device configurations or manipulate monitoring data, potentially leading to false security alerts or complete network visibility loss. Organizations relying on LibreNMS for network monitoring and security operations would face significant operational disruption if this vulnerability is exploited. The vulnerability affects the core device management functionality, which is essential for network administrators to maintain their monitoring infrastructure. Mitigation efforts should focus on immediate patching to version 1.65.1 or later, along with implementing additional security controls such as network segmentation, monitoring for unusual database access patterns, and regular security assessments of the monitoring infrastructure. Organizations should also consider implementing web application firewalls to detect and block malicious SQL injection attempts, and conduct thorough security reviews of all input handling mechanisms within the application.