A critical vulnerability, identified as CVE-2022-44786, has been discovered in the popular web application suite, Appalti & Contratti, version 9.12.2. The vulnerability allows for Local File Inclusion (LFI) attacks through the manipulation of the href parameter in specified JSP pages. This security threat presents potential risks to web applications since attackers can access sensitive files stored on the server, which can lead to data leaks, code execution, or even take over the entire web application.

In this post, we'll be diving deep into the details of the exploit, examining the vulnerable code snippet, exploring how the attack is carried out, and providing valuable references to the original sources of information.

Vulnerable Code Snippet

The vulnerability exists in the way the ApriPagina.do POST and GET requests handle the href parameter. The affected JSP pages rely on this parameter for specifying which page is to be rendered. Unfortunately, the parameter's value is not properly sanitized, allowing an attacker to manipulate it and access any arbitrary local file. The vulnerable portion of the code is as follows:

//ApriPagina.do - JSP page rendering
String page = request.getParameter("href");
if (page != null) {
    RequestDispatcher rd = request.getRequestDispatcher(page);
    rd.forward(request, response);
}

Exploit Details

To exploit this vulnerability, an attacker sends a specially crafted HTTP POST or GET request to the target application with a manipulated href parameter. The attacker includes a file path pointing to a sensitive file on the server using directory traversal techniques. For example, an attacker might use the following request to view the web application's configuration file:

GET /ApriPagina.do?href=../../../../../../web.config HTTP/1.1
Host: example.com

Once the request is submitted, the web application returns the content of the specified file, allowing the attacker to gain unauthorized access to sensitive information, like database credentials and server configuration settings.

Remediation

To fix this vulnerability, it is crucial to implement proper input validation and sanitization techniques, specifically for the href parameter. Here's an example of a code fix that can help prevent LFI attacks:

//ApriPagina.do - JSP page rendering with input validation
String page = request.getParameter("href");
if (page != null) {
    // Sanitize the input to prevent directory traversal
    page = page.replace("..", "");

    // Ensure the requested page is within the allowed directory
    if (page.startsWith("/allowed_directory/")) {
        RequestDispatcher rd = request.getRequestDispatcher(page);
        rd.forward(request, response);
    } else {
        // If the request is outside the allowed directory, throw an error
        response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Invalid page request");
    }
}

The original security advisory for CVE-2022-44786 can be found at the following locations

- CVE-2022-44786 NVD Entry
- Appalti & Contratti Security Notice

Conclusion

In conclusion, CVE-2022-44786 is a serious Local File Inclusion vulnerability affecting Appalti & Contratti 9.12.2, and it is crucial that the vulnerability is patched as soon as possible to prevent potential exploitation. Developers and administrators must always prioritize input validation and proper parameter sanitization when building and maintaining web applications. By staying vigilant and keeping applications up-to-date, it is possible to mitigate the risks associated with security vulnerabilities and maintain the integrity of web applications and user data.

Timeline

Published on: 11/21/2022 23:15:00 UTC
Last modified on: 11/23/2022 16:02:00 UTC