CVE-2022-31565
📋 TL;DR
This vulnerability allows attackers to read arbitrary files on the server through absolute path traversal in the yogson/syrabond repository. It affects any system running this software with the vulnerable Flask send_file implementation. Attackers can access sensitive files like configuration files, credentials, or source code.
💻 Affected Systems
- yogson/syrabond repository
📦 What is this software?
Syrabond by Syrabond Project
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise through reading sensitive files like SSH keys, database credentials, or configuration files leading to lateral movement and data exfiltration.
Likely Case
Unauthorized access to sensitive server files containing application secrets, user data, or system information.
If Mitigated
Limited impact with proper file system permissions and network segmentation preventing access to critical system files.
🎯 Exploit Status
Simple HTTP requests with crafted paths can exploit this vulnerability. Public GitHub issues demonstrate the exploitation technique.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch exists. Remove or replace the vulnerable software with a secure alternative.
🔧 Temporary Workarounds
Implement path validation middleware
allAdd middleware to validate and sanitize file paths before passing to send_file
# Python Flask middleware example
from flask import abort
import os
def validate_path(path):
# Normalize and validate path
normalized = os.path.normpath(path)
if '..' in normalized or normalized.startswith('/'):
abort(403)
return normalized
Restrict file system access
linuxUse chroot/jail or containerization to limit file system access
# Docker example
FROM python:3.9
WORKDIR /app
COPY . .
RUN chmod -R 755 /app
USER nobody
🧯 If You Can't Patch
- Remove the syrabond software from production systems
- Implement strict network segmentation and WAF rules to block path traversal patterns
🔍 How to Verify
Check if Vulnerable:
Check if your application uses yogson/syrabond repository version from before 2020-05-25 and uses Flask send_file without path validation.Check Version:
Check package dependencies or repository commit history for syrabond usageVerify Fix Applied:
Test with crafted requests containing absolute paths (e.g., /etc/passwd) and verify they return 403/404 errors instead of file contents.📡 Detection & Monitoring
Log Indicators:
- HTTP requests with absolute paths like /etc/passwd, /proc/self/environ
- Unusual file access patterns from web application logs
Network Indicators:
- HTTP requests containing .. or absolute paths in URL parameters
SIEM Query:
web_access_logs | where url contains "/etc/" or url contains "/proc/" or url contains ".."