CVE-2022-25299
📋 TL;DR
CVE-2022-25299 is a path traversal vulnerability in the cesanta/mongoose library's mg_http_upload() function that allows attackers to write files outside the intended upload directory by manipulating file names. This affects any application using mongoose versions before 7.6 for file upload functionality. Attackers could potentially overwrite critical system files or deploy malicious payloads.
💻 Affected Systems
- cesanta/mongoose
📦 What is this software?
Mongoose by Cesanta
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution via overwriting system files, configuration files, or deploying web shells, leading to complete system compromise.
Likely Case
Unauthorized file writes to sensitive directories, potentially enabling data manipulation, privilege escalation, or denial of service.
If Mitigated
Limited impact if proper input validation and file permission restrictions are in place, preventing writes to critical locations.
🎯 Exploit Status
Exploitation requires the application to have file upload functionality using the vulnerable function. Simple path traversal payloads can be used.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.6 and later
Vendor Advisory: https://github.com/cesanta/mongoose/commit/c65c8fdaaa257e0487ab0aaae9e8f6b439335945
Restart Required: Yes
Instructions:
1. Update mongoose to version 7.6 or later. 2. Rebuild and redeploy the application. 3. Restart the service to apply changes.
🔧 Temporary Workarounds
Input validation for file names
allImplement server-side validation to reject file names containing path traversal sequences (../, ..\) before processing uploads.
Restrict upload directory permissions
linuxSet strict file system permissions on the upload directory to prevent writes outside the intended location.
chmod 750 /path/to/upload/directory
🧯 If You Can't Patch
- Disable file upload functionality if not essential.
- Implement a web application firewall (WAF) with rules to block path traversal patterns in file names.
🔍 How to Verify
Check if Vulnerable:
Check if the application uses mongoose version earlier than 7.6 and has file upload functionality via mg_http_upload().Check Version:
Check the application's dependency file (e.g., package.json, go.mod) or run the application with version flag if available.Verify Fix Applied:
Confirm mongoose version is 7.6 or later and test file uploads with path traversal payloads to ensure they are rejected.📡 Detection & Monitoring
Log Indicators:
- Failed file upload attempts with suspicious file names containing ../ or ..\
- Unexpected file writes outside the upload directory
Network Indicators:
- HTTP POST requests to upload endpoints with file names containing path traversal sequences
SIEM Query:
source="web_logs" AND (uri_path="/upload" OR method="POST") AND file_name MATCHES "*../*"