CVE-2022-31579
📋 TL;DR
This vulnerability allows attackers to read arbitrary files on the server through absolute path traversal in the ralphjzhang/iasset repository. It affects any system running this GitHub repository's code before May 4, 2022. The vulnerability occurs because Flask's send_file function is used without proper path validation.
💻 Affected Systems
- ralphjzhang/iasset repository
📦 What is this software?
Iasset by Iasset Project
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise through reading sensitive files like /etc/passwd, SSH keys, configuration files, or database credentials, potentially leading to full system takeover.
Likely Case
Unauthorized access to sensitive files containing credentials, configuration data, or user information stored on the server.
If Mitigated
Limited impact with proper file permissions and network segmentation, but still potential information disclosure.
🎯 Exploit Status
Path traversal vulnerabilities are well-understood and easily exploitable with simple HTTP requests.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 2022-05-04
Vendor Advisory: https://github.com/github/securitylab/issues/669
Restart Required: Yes
Instructions:
1. Update to the latest version of ralphjzhang/iasset repository
2. Replace vulnerable send_file usage with secure implementation
3. Restart the Flask application
🔧 Temporary Workarounds
Input Validation Middleware
allAdd middleware to validate and sanitize file paths before send_file is called
# Add path validation in Flask route handlers
from werkzeug.utils import safe_join
import os
# Replace vulnerable code with:
def get_file(filename):
safe_path = safe_join('/intended/directory', filename)
if safe_path is None or not os.path.exists(safe_path):
abort(404)
return send_file(safe_path)
Web Application Firewall Rules
allBlock requests containing path traversal sequences
# Example WAF rule to block path traversal
# Block requests with: ../, ..\, /etc/, /proc/, absolute paths
🧯 If You Can't Patch
- Implement strict file system permissions to limit accessible directories
- Deploy network segmentation to isolate vulnerable systems from sensitive data
🔍 How to Verify
Check if Vulnerable:
Review Flask route handlers for unsafe send_file usage with user-controlled input, test with path traversal payloads like '../../etc/passwd'Check Version:
Check repository commit date or version metadata, ensure it's after 2022-05-04Verify Fix Applied:
Test that path traversal attempts return 404 errors instead of file contents, verify send_file uses validated paths📡 Detection & Monitoring
Log Indicators:
- HTTP requests containing '../' sequences
- 404 errors for non-existent files in unexpected directories
- Access to sensitive file paths in access logs
Network Indicators:
- Unusual file requests from single IPs
- Requests for known sensitive files like /etc/passwd
SIEM Query:
source="web_logs" AND (uri="*../*" OR uri="*/etc/*" OR uri="*/proc/*")