CVE-2023-26820
📋 TL;DR
CVE-2023-26820 is a path traversal vulnerability in siteproxy v1.0 that allows attackers to read arbitrary files on the server by manipulating file paths through the index.js component. This affects all users running the vulnerable version of siteproxy, potentially exposing sensitive server files.
💻 Affected Systems
- siteproxy
📦 What is this software?
Siteproxy by Siteproxy Project
⚠️ Risk & Real-World Impact
Worst Case
Complete server file system disclosure including configuration files, credentials, and sensitive application data leading to full system compromise.
Likely Case
Unauthorized reading of sensitive files such as configuration files, logs, or source code, potentially enabling further attacks.
If Mitigated
Limited impact with proper file permissions and network segmentation preventing access to critical system files.
🎯 Exploit Status
The GitHub issue shows proof-of-concept exploitation details. The vulnerability is simple to exploit with basic HTTP requests.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.0.1 or later
Vendor Advisory: https://github.com/netptop/siteproxy/issues/67
Restart Required: Yes
Instructions:
1. Stop the siteproxy service. 2. Update to v1.0.1 or later using npm update siteproxy. 3. Restart the service.
🔧 Temporary Workarounds
Input Validation Filter
allAdd path traversal validation to filter malicious input before processing.
// Add path traversal check in index.js
const path = require('path');
const safePath = path.normalize(userInput).replace(/^(\/|\\)+/, '');
File Access Restriction
allImplement file access restrictions to limit which directories can be accessed.
// Restrict file access to specific directory
const allowedDir = '/var/www/safe';
const requestedPath = path.join(allowedDir, userInput);
🧯 If You Can't Patch
- Implement network segmentation to isolate siteproxy from sensitive systems
- Deploy a web application firewall (WAF) with path traversal protection rules
🔍 How to Verify
Check if Vulnerable:
Test by attempting to access files outside the intended directory using ../ sequences in requests to the siteproxy endpoint.Check Version:
npm list siteproxy | grep siteproxyVerify Fix Applied:
After patching, attempt the same path traversal attacks to confirm they are blocked.📡 Detection & Monitoring
Log Indicators:
- Multiple requests containing ../ sequences
- Access to unusual file paths in logs
- Failed file access attempts outside expected directories
Network Indicators:
- HTTP requests with ../ patterns in URL parameters
- Unusual file extension requests to siteproxy endpoints
SIEM Query:
source="siteproxy" AND (url="*../*" OR url="*..\\*")