CVE-2022-31513
📋 TL;DR
This vulnerability allows attackers to perform absolute path traversal attacks in the BolunHan/Krypton repository, enabling unauthorized file access. It affects users running vulnerable versions of this software that use Flask's send_file function unsafely. The high CVSS score indicates significant security impact.
💻 Affected Systems
- BolunHan/Krypton repository
📦 What is this software?
Krypton by Krypton Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through arbitrary file read/write, potentially leading to sensitive data exposure, credential theft, or remote code execution.
Likely Case
Unauthorized access to sensitive files on the server, including configuration files, credentials, and application data.
If Mitigated
Limited impact with proper input validation, file access restrictions, and security controls in place.
🎯 Exploit Status
Path traversal vulnerabilities are commonly exploited and require minimal technical skill.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 2021-06-03 with proper path validation
Vendor Advisory: https://github.com/github/securitylab/issues/669
Restart Required: Yes
Instructions:
1. Update to latest version of Krypton repository. 2. Ensure Flask send_file calls include proper path validation. 3. Restart the application service.
🔧 Temporary Workarounds
Input Validation Middleware
allAdd middleware to validate and sanitize file paths before processing
# Add path validation in Flask routes
from werkzeug.utils import secure_filename
secure_path = secure_filename(requested_path)
File Access Restrictions
linuxImplement chroot jail or containerization to limit file system access
# Run application in restricted environment
sudo chroot /safe/path /app/start.sh
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block path traversal patterns
- Restrict network access to vulnerable systems and implement strict file permissions
🔍 How to Verify
Check if Vulnerable:
Review Flask route handlers for unsafe send_file usage without path validationCheck Version:
Check repository commit date or version metadataVerify Fix Applied:
Test with path traversal payloads (e.g., ../../../etc/passwd) to confirm blocked access📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns
- Requests containing ../ sequences
- Access to sensitive system files
Network Indicators:
- HTTP requests with path traversal payloads
- Unusual file download patterns
SIEM Query:
source="web_logs" AND (uri="*../*" OR uri="*..\\*" OR status=403 OR status=404)