CVE-2022-31553
📋 TL;DR
This vulnerability allows attackers to read arbitrary files on the server through absolute path traversal in the rainsoupah/sleep-learner GitHub repository. It affects any system running this software with the vulnerable Flask send_file implementation. The high CVSS score reflects the potential for sensitive data exposure.
💻 Affected Systems
- rainsoupah/sleep-learner GitHub repository
📦 What is this software?
Sleep Learner by Sleep Learner Project
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise through reading sensitive files like /etc/passwd, SSH keys, or configuration files containing credentials.
Likely Case
Unauthorized access to sensitive application files, configuration data, or user data stored on the server.
If Mitigated
Limited impact if proper file permissions and web server configurations restrict access to sensitive directories.
🎯 Exploit Status
Path traversal vulnerabilities are commonly exploited and require minimal technical skill.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 2021-02-21
Vendor Advisory: https://github.com/github/securitylab/issues/669#issuecomment-1117265726
Restart Required: Yes
Instructions:
1. Update to the latest version of the repository. 2. Replace unsafe Flask send_file usage with proper path validation. 3. Restart the application server.
🔧 Temporary Workarounds
Implement Path Validation
allAdd input validation to sanitize file paths before passing to send_file
# Python code to validate paths
import os
from flask import abort
def safe_send_file(path):
base_dir = os.path.abspath('allowed_directory')
requested_path = os.path.abspath(os.path.join(base_dir, path))
if not requested_path.startswith(base_dir):
abort(403)
return send_file(requested_path)
Web Server Restrictions
linuxConfigure web server to restrict access to sensitive directories
# Nginx example
location ~ /\. {
deny all;
}
# Apache example
<DirectoryMatch "^/.*/\.">
Order deny,allow
Deny from all
</DirectoryMatch>
🧯 If You Can't Patch
- Implement strict file permission controls on the server
- Deploy web application firewall with path traversal rules
🔍 How to Verify
Check if Vulnerable:
Review Flask code for unsafe send_file usage without path validation. Test by attempting to access files outside allowed directories.Check Version:
Check repository commit history or version metadata for dates after 2021-02-21Verify Fix Applied:
Test that path traversal attempts return 403/404 errors instead of file contents. Verify code implements proper path sanitization.📡 Detection & Monitoring
Log Indicators:
- Multiple 403/404 errors for path traversal attempts
- Unusual file access patterns in application logs
Network Indicators:
- HTTP requests containing '../' sequences
- Requests for known sensitive files
SIEM Query:
source="web_logs" AND (uri="*../*" OR uri="*/etc/passwd" OR uri="*/.ssh/*")