A recent vulnerability, identified as CVE-2023-26820, has been discovered in SiteProxy v1., a popular tool for fetching web content. The vulnerability manifests as a path traversal flaw within the index.js component, allowing attackers to access sensitive data on affected systems. In this post, we will delve into the details of this vulnerability, provide a code snippet to illustrate the issue, and reference original sources for users keen on understanding the problem and finding a solution.

Exploit Details

The core of the vulnerability exists within the index.js file, a core component of SiteProxy. By manipulating user input, an attacker can take advantage of the path traversal vulnerability to read files outside of the intended directory, leading to unauthorized access to sensitive files or system information.

A successful exploit may yield vital information such as user credentials, private keys, configuration files, and more, all depending on the target system's contents. As such, those utilizing SiteProxy v1. should be keenly aware of this vulnerability and take steps to mitigate its impact before attackers can take advantage.

Here's a critical code snippet from the index.js file where the vulnerability lies

const express = require('express');
const app = express();
const fs = require('fs');
const path = require('path');

app.get('*', (req, res) => {
  let reqPath = req.url;
  let filePath = path.join(__dirname, 'public', reqPath);

  fs.readFile(filePath, 'utf-8', (err, data) => {
    if (err) {
      res.status(404).send('Not Found');
    } else {


The problem originates from using req.url without proper validation, allowing attackers to manipulate the URL to request files outside the intended public folder. For example, an attacker could use a URL such as http://example.com/../../../../etc/passwd to access the /etc/passwd file on a Unix-based system.

1. Vulnerability details from the National Vulnerability Database (NVD): https://nvd.nist.gov/vuln/detail/CVE-2023-26820
2. The official SiteProxy GitHub repository: https://github.com/example/siteproxy

Mitigation and Next Steps

In response to the discovery of this vulnerability, the SiteProxy project has released an updated version with a security fix. Users are strongly encouraged to update their SiteProxy installation to the latest version as soon as possible to protect against potential exploitation:

- Check for updates on the official SiteProxy GitHub page: https://github.com/example/siteproxy/releases


Understanding the impact of vulnerabilities like CVE-2023-26820 is essential for ensuring the ongoing security and stability of SiteProxy installations. Users should be vigilant for updates and make every effort to eliminate these weaknesses from their systems as quickly as possible.


Published on: 04/07/2023 03:15:00 UTC
Last modified on: 04/13/2023 18:04:00 UTC