CVE-2022-31583
📋 TL;DR
This vulnerability allows attackers to read arbitrary files on the server through absolute path traversal in the AutomatedQuizEval repository. It affects any system running this Flask-based quiz evaluation application with the vulnerable code. Attackers can access sensitive files like configuration files, passwords, or source code.
💻 Affected Systems
- sravaniboinepelli/AutomatedQuizEval
📦 What is this software?
Automatedquizeval by Automatedquizeval Project
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise through reading sensitive files like SSH keys, database credentials, or configuration files leading to further attacks.
Likely Case
Exfiltration of sensitive application data, configuration files, or source code that could enable additional attacks.
If Mitigated
Limited impact with proper file permissions and network segmentation preventing access to critical system files.
🎯 Exploit Status
The vulnerability is in the Flask send_file function usage, making exploitation straightforward with simple HTTP requests.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: N/A
Restart Required: No
Instructions:
1. Remove or replace the vulnerable repository code
2. Implement proper input validation for file paths
3. Use Flask's safe file serving methods with path sanitization
🔧 Temporary Workarounds
Input Validation and Sanitization
allAdd validation to ensure file paths are within allowed directories and sanitize user input.
# Python code to sanitize paths
import os
from werkzeug.utils import safe_join
safe_path = safe_join(base_directory, user_input_path)
if safe_path is None:
return 'Invalid path'
# Use safe_path with send_file
Web Application Firewall Rules
allBlock requests containing path traversal sequences like '../', '..\', or absolute paths.
# Example WAF rule to block path traversal
# Block requests with:
# ../ or ..\ in URL parameters
# Absolute paths starting with /etc/, /root/, etc.
🧯 If You Can't Patch
- Isolate the application in a restricted network segment with minimal file system access
- Implement strict file permissions and remove sensitive files from accessible directories
🔍 How to Verify
Check if Vulnerable:
Review the Flask application code for unsafe use of send_file() with user-controlled input without proper path validation.Check Version:
# Check if using vulnerable repository
git log --oneline | grep -i "2020-04-27"
# Or check repository metadataVerify Fix Applied:
Test that attempts to access files outside allowed directories (like /etc/passwd or ../../config.py) return errors instead of file contents.📡 Detection & Monitoring
Log Indicators:
- HTTP requests with path traversal sequences (../, ..\)
- Requests for sensitive file paths like /etc/passwd, /proc/self/environ
- Unusual file access patterns from single IPs
Network Indicators:
- HTTP requests with encoded path traversal sequences (%2e%2e%2f)
- Rapid sequential requests for different file paths
SIEM Query:
source="web_logs" AND (url="*../*" OR url="*..\\*" OR url="/etc/*" OR url="/root/*")