CVE-2022-36746 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 oxidized-cfg-check.inc.php.
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Analysis
by VulDB Data Team • 10/10/2022
The vulnerability identified as CVE-2022-36746 affects LibreNMS version 22.6.0 and represents a cross-site scripting vulnerability within the oxidized-cfg-check.inc.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 configuration management interface where user inputs are not adequately filtered before being rendered back to users in web pages. The specific component oxidized-cfg-check.inc.php appears to process configuration data from network devices and displays this information within the user interface without proper HTML escaping or context-aware output encoding.
The technical flaw stems from the application's failure to implement proper security controls for handling untrusted data in web contexts. When users interact with the configuration checking functionality, malicious payloads can be injected into input fields or configuration parameters that are subsequently reflected in the web page output. This creates an opportunity for attackers to execute arbitrary JavaScript code in the context of other users' browsers, potentially leading to session hijacking, credential theft, or unauthorized actions within the application. The vulnerability aligns with CWE-79 which categorizes cross-site scripting flaws as weaknesses in input validation and output encoding. The attack vector likely involves an attacker crafting malicious input that gets stored or processed by the oxidized-cfg-check.inc.php component, then executed when other users view the affected pages.
The operational impact of this vulnerability is significant for organizations relying on LibreNMS for network monitoring and management. An attacker could exploit this XSS vulnerability to gain unauthorized access to network device configurations, potentially leading to reconnaissance of network infrastructure and identification of sensitive information. The vulnerability could also enable privilege escalation attacks if the application's authentication and authorization mechanisms are bypassed through session manipulation. Users with administrative privileges could be targeted to execute malicious scripts that capture session cookies or redirect users to phishing sites. This vulnerability directly relates to ATT&CK technique T1531 which involves use of valid accounts to conduct privilege escalation attacks, and T1566 which encompasses social engineering tactics through malicious links or payloads.
Mitigation strategies for CVE-2022-36746 should prioritize immediate patching of the LibreNMS application to version 22.6.1 or later, which contains the necessary fixes for the XSS vulnerability. Organizations should implement proper input validation and output encoding controls throughout the application, ensuring that all user-supplied data is sanitized before being processed or displayed. The implementation of Content Security Policy headers can provide additional protection against XSS attacks by restricting script execution within the application. Network segmentation and monitoring should be enhanced to detect potential exploitation attempts, while regular security assessments should be conducted to identify similar vulnerabilities in other components. Additionally, user education regarding suspicious links and unexpected behavior in network monitoring tools can help reduce the risk of successful exploitation. The vulnerability demonstrates the importance of maintaining up-to-date software versions and implementing defense-in-depth strategies that include both perimeter security controls and application-level protections to prevent cross-site scripting attacks.