CVE-2021-20651
📋 TL;DR
This directory traversal vulnerability in ELECOM File Manager allows remote attackers to create or overwrite arbitrary files within directories accessible by the application. Attackers can potentially write malicious files to sensitive locations, leading to further compromise. All versions of ELECOM File Manager are affected.
💻 Affected Systems
- ELECOM File Manager
📦 What is this software?
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment by writing malicious files to executable locations.
Likely Case
File system manipulation allowing attackers to overwrite configuration files, install backdoors, or disrupt application functionality.
If Mitigated
Limited impact if application runs with minimal privileges and file system permissions restrict write access to sensitive directories.
🎯 Exploit Status
The vulnerability allows unauthenticated exploitation via unspecified vectors, suggesting relatively straightforward attack paths.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 2.1.4.002 and later
Vendor Advisory: https://www.elecom.co.jp/news/security/20210126-01/
Restart Required: Yes
Instructions:
1. Download the latest version from ELECOM website. 2. Uninstall the current version. 3. Install the updated version. 4. Restart the system.
🔧 Temporary Workarounds
Network Access Restriction
windowsBlock network access to ELECOM File Manager using firewall rules
netsh advfirewall firewall add rule name="Block ELECOM File Manager" dir=in action=block program="C:\Program Files\ELECOM\File Manager\elecomfm.exe" enable=yes
Application Removal
windowsUninstall ELECOM File Manager if not required
appwiz.cpl
🧯 If You Can't Patch
- Disable or uninstall ELECOM File Manager entirely
- Implement strict network segmentation and firewall rules to isolate affected systems
🔍 How to Verify
Check if Vulnerable:
Check if ELECOM File Manager is installed and version is below 2.1.4.002Check Version:
wmic product where name="ELECOM File Manager" get versionVerify Fix Applied:
Verify installed version is 2.1.4.002 or higher via Control Panel > Programs and Features📡 Detection & Monitoring
Log Indicators:
- Unusual file creation/modification events in application directories
- Directory traversal patterns in web server logs if web-accessible
Network Indicators:
- Unexpected network connections to/from ELECOM File Manager ports
- Anomalous file transfer patterns
SIEM Query:
source="*elecom*" AND (event_type="file_create" OR event_type="file_modify") AND path="*../*"