Source: cve@mitre.org
Cross-site scripting (XSS) vulnerability in the handle_request function in lib/HTTPServer.pm in Monitorix before 3.4.0 allows remote attackers to inject arbitrary web script or HTML via the PATH_INFO.
Monitorix versions prior to 3.4.0 are vulnerable to a cross-site scripting (XSS) attack, allowing attackers to inject malicious scripts into the web application. This vulnerability, stemming from improper handling of user-supplied input in the handle_request function, could lead to session hijacking, data theft, and website defacement.
Step 1: Payload Delivery: The attacker crafts a malicious URL containing a JavaScript payload within the PATH_INFO component. For example: http://<target>/cgi-bin/monitorix/<malicious_script>. The <malicious_script> contains the XSS payload (e.g., <script>alert('XSS')</script>).
Step 2: Request Submission: The victim, either through direct interaction or social engineering, accesses the crafted URL.
Step 3: Server Processing: The Monitorix server receives the HTTP request and processes it, specifically calling the handle_request function.
Step 4: Vulnerable Code Execution: The handle_request function retrieves the PATH_INFO from the request.
Step 5: Unsanitized Output: The handle_request function incorporates the unsanitized PATH_INFO (including the attacker's payload) into the HTML response.
Step 6: Browser Rendering: The victim's web browser receives the HTML response, which now includes the attacker's JavaScript payload.
Step 7: Payload Execution: The browser executes the injected JavaScript, allowing the attacker to perform actions such as stealing cookies, redirecting the user, or defacing the website.
The vulnerability lies within the handle_request function in lib/HTTPServer.pm of Monitorix. The function fails to properly sanitize the PATH_INFO parameter before incorporating it into the HTML response. This allows an attacker to inject malicious JavaScript code within the PATH_INFO portion of a crafted URL. The lack of input validation and output encoding allows the injected script to be executed in the context of the victim's browser, leading to XSS. The root cause is a missing or inadequate input validation and output encoding mechanism for the PATH_INFO parameter, which is directly reflected in the HTML response without proper sanitization. This allows for the injection of arbitrary HTML and JavaScript.
This vulnerability is not directly associated with specific APT groups or malware families. However, XSS vulnerabilities are commonly used by various threat actors for initial access, credential harvesting, and data exfiltration. The lack of specific attribution does not diminish the risk. CISA KEV status: Not Listed
Monitor web server logs for suspicious HTTP requests containing JavaScript payloads in the PATH_INFO parameter (e.g., <script>, onerror, onload).
Implement a Web Application Firewall (WAF) to detect and block XSS attempts.
Monitor network traffic for unusual patterns, such as a sudden increase in requests to specific URLs or the presence of JavaScript code in HTTP responses.
Use a security scanner to identify XSS vulnerabilities in the web application.
Analyze HTTP response bodies for the presence of unexpected JavaScript code.
Upgrade Monitorix to version 3.4.0 or later.
Implement proper input validation to sanitize the PATH_INFO parameter, ensuring that it only contains allowed characters and formats.
Implement output encoding (e.g., HTML entity encoding) to escape special characters in the PATH_INFO before displaying it in the HTML response.
Use a Content Security Policy (CSP) to restrict the sources from which the browser can load resources, mitigating the impact of XSS attacks.
Regularly scan the web application for vulnerabilities using automated tools and manual penetration testing.