CVE-2021-41185
📋 TL;DR
CVE-2021-41185 is a path traversal vulnerability in Mycodo environmental monitoring systems that allows attackers to download files outside intended directories. Anyone with access to vulnerable endpoints can exploit this to access sensitive system files. Users running Mycodo versions prior to 8.12.7 are affected.
💻 Affected Systems
- Mycodo
📦 What is this software?
Mycodo by Mycodo Project
⚠️ Risk & Real-World Impact
Worst Case
Attackers could download sensitive configuration files, credentials, or system files leading to complete system compromise and data exfiltration.
Likely Case
Unauthorized access to sensitive configuration files and system information, potentially enabling further attacks.
If Mitigated
With proper network segmentation and access controls, impact limited to isolated monitoring systems.
🎯 Exploit Status
Exploit requires only HTTP requests to vulnerable endpoints; proof-of-concept available in GitHub issues.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 8.12.7
Vendor Advisory: https://github.com/kizniche/Mycodo/security/advisories/GHSA-252r-94ph-m229
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Stop Mycodo service. 3. Update to version 8.12.7 via package manager or manual installation. 4. Restart Mycodo service.
🔧 Temporary Workarounds
Manual patch application
linuxApply the security fix from the GitHub commit without full upgrade
git apply https://github.com/kizniche/Mycodo/commit/23ac5dd422029c2b6ae1701a3599b6d41b66a6a9.patch
🧯 If You Can't Patch
- Restrict network access to Mycodo endpoints using firewall rules
- Implement web application firewall (WAF) rules to block path traversal patterns
🔍 How to Verify
Check if Vulnerable:
Check Mycodo version; if <8.12.7, system is vulnerable. Test with controlled path traversal attempt.Check Version:
mycodo --version || check /opt/mycodo/version.txtVerify Fix Applied:
After patching, attempt path traversal exploitation; should return error or be blocked.📡 Detection & Monitoring
Log Indicators:
- HTTP requests with '../' patterns in URLs
- Unusual file access patterns from web endpoints
- 401/403 errors followed by successful file downloads
Network Indicators:
- HTTP requests containing path traversal sequences to Mycodo endpoints
- Unusual file download patterns from monitoring system
SIEM Query:
source="mycodo.log" AND (url="*../*" OR status=200 AND bytes>1000000)🔗 References
- https://github.com/kizniche/Mycodo/commit/23ac5dd422029c2b6ae1701a3599b6d41b66a6a9
- https://github.com/kizniche/Mycodo/issues/1105
- https://github.com/kizniche/Mycodo/releases/tag/v8.12.7
- https://github.com/kizniche/Mycodo/security/advisories/GHSA-252r-94ph-m229
- https://github.com/kizniche/Mycodo/commit/23ac5dd422029c2b6ae1701a3599b6d41b66a6a9
- https://github.com/kizniche/Mycodo/issues/1105
- https://github.com/kizniche/Mycodo/releases/tag/v8.12.7
- https://github.com/kizniche/Mycodo/security/advisories/GHSA-252r-94ph-m229
