CVE-2022-31587
📋 TL;DR
This vulnerability allows attackers to perform absolute path traversal attacks by exploiting unsafe usage of Flask's send_file function in the yuriyouzhou/KG-fashion-chatbot repository. Attackers can potentially access sensitive files outside the intended directory. Anyone using this GitHub repository through May 22, 2018 is affected.
💻 Affected Systems
- yuriyouzhou/KG-fashion-chatbot repository
📦 What is this software?
Kg Fashion Chatbot by Kg Fashion Chatbot Project
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise through arbitrary file read, potentially leading to credential theft, sensitive data exposure, and further system exploitation.
Likely Case
Unauthorized access to sensitive configuration files, source code, or user data stored on the server.
If Mitigated
Limited impact with proper file system permissions and input validation in place.
🎯 Exploit Status
Path traversal vulnerabilities are well-understood and easily exploitable with minimal technical skill.
🛠️ 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 send_file with safe path handling
4. Consider using a maintained alternative
🔧 Temporary Workarounds
Input Validation Implementation
allAdd strict input validation to sanitize file path parameters before passing to send_file
# Python code to validate paths
import os
from werkzeug.utils import safe_join
safe_path = safe_join(base_directory, user_input)
if not os.path.exists(safe_path):
abort(404)
Web Application Firewall Rules
allImplement WAF rules to block path traversal patterns
# Example ModSecurity rule
SecRule ARGS "@contains .." "id:1001,phase:2,deny,msg:'Path Traversal Attempt'"
🧯 If You Can't Patch
- Isolate the vulnerable application in a restricted network segment
- Implement strict file system permissions to limit accessible directories
🔍 How to Verify
Check if Vulnerable:
Review Flask route handlers using send_file() to check for unsanitized user input in file pathsCheck Version:
Check repository commit history and ensure no code from before 2018-05-22 is in useVerify Fix Applied:
Test with path traversal payloads (e.g., ../../../etc/passwd) to ensure proper blocking📡 Detection & Monitoring
Log Indicators:
- Multiple 404 errors with path traversal patterns
- Unusual file access patterns in application logs
Network Indicators:
- HTTP requests containing ../ patterns in URL parameters
- Unusual file extensions in requests
SIEM Query:
source="web_logs" AND (uri="*../*" OR params="*../*")