CVE-2022-36745 in LibreNMS
Summary
by MITRE • 08/31/2022
LibreNMS v22.6.0 was discovered to contain a cross-site scripting (XSS) vulnerability via the component print-customoid.php.
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Analysis
by VulDB Data Team • 10/10/2022
The vulnerability identified as CVE-2022-36745 represents a critical cross-site scripting flaw within LibreNMS version 22.6.0, specifically affecting the print-customoid.php component. This issue arises from insufficient input validation and output sanitization mechanisms that fail to properly handle malicious user-supplied data. The vulnerability exists in the web application's handling of custom OID (Object Identifier) data, which is commonly used in network monitoring and management systems to define specific metrics and parameters. When a user submits crafted malicious input through the print-customoid.php interface, the application fails to adequately sanitize this data before rendering it within the web page context, creating an avenue for attackers to inject malicious scripts.
The technical implementation of this XSS vulnerability stems from the application's failure to properly escape or encode user-controllable data before incorporating it into dynamic HTML content. According to CWE-79, this represents a classic cross-site scripting weakness where the application does not validate or sanitize input data before using it in web responses. The vulnerability can be exploited through various attack vectors including reflected and stored XSS scenarios, depending on how the malicious input is processed and stored within the system. The impact is particularly concerning in network monitoring environments where LibreNMS serves as a central management interface for critical infrastructure components.
From an operational perspective, this vulnerability poses significant risks to organizations relying on LibreNMS for network monitoring and management. Attackers could leverage this flaw to execute malicious scripts in the context of authenticated users' browsers, potentially leading to session hijacking, credential theft, or unauthorized access to network monitoring data. The attack surface is broad as the vulnerability affects the core printing functionality that users frequently interact with during routine network management tasks. According to ATT&CK framework, this vulnerability maps to T1566 (Phishing) and T1071.004 (Application Layer Protocol: DNS) as attackers could use the XSS to redirect users to malicious domains or harvest credentials. The vulnerability also aligns with T1584 (Compromise Infrastructure) as it could be used to establish persistent access through malicious script execution.
Organizations should immediately implement mitigations including upgrading to a patched version of LibreNMS, as the vulnerability was addressed in subsequent releases. Network administrators should also consider implementing input validation rules at the application level, ensuring that all user-supplied data undergoes proper sanitization before being processed or displayed. The implementation of Content Security Policy (CSP) headers can provide additional protection against XSS attacks by restricting script execution within the application context. Additionally, regular security assessments and input validation testing should be conducted to identify similar vulnerabilities in other components of the LibreNMS system. Organizations should also consider implementing web application firewalls to provide an additional layer of protection against exploitation attempts targeting this and similar vulnerabilities.