CVE-2025-55383
📋 TL;DR
Moss versions before 0.15 have an unrestricted file upload vulnerability that allows attackers to upload arbitrary files to any location on the server. This affects all systems running vulnerable Moss versions with the upload function enabled. Attackers can achieve remote code execution or server compromise.
💻 Affected Systems
- Moss
⚠️ 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
Complete server takeover via remote code execution by uploading malicious scripts or binaries to executable locations.
Likely Case
Webshell deployment leading to data theft, lateral movement, or ransomware deployment.
If Mitigated
Limited impact if file uploads are disabled or restricted to non-executable directories with proper permissions.
🎯 Exploit Status
Simple HTTP POST requests with file uploads can exploit this vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.15
Vendor Advisory: https://github.com/deep-project/moss/issues/16
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Stop Moss service. 3. Upgrade to version 0.15 or later. 4. Restart Moss service. 5. Verify upload restrictions are properly configured.
🔧 Temporary Workarounds
Disable upload functionality
allCompletely disable file uploads in Moss configuration
Edit moss config file and set 'upload_enabled: false'
Restrict upload directory permissions
linuxSet upload directory to read-only for web user
chmod 755 /path/to/upload/directory
chown root:root /path/to/upload/directory
🧯 If You Can't Patch
- Implement web application firewall (WAF) rules to block file uploads with executable extensions
- Monitor upload directories for suspicious files and implement file integrity monitoring
🔍 How to Verify
Check if Vulnerable:
Check Moss version and attempt to upload a file with executable extension to arbitrary locationCheck Version:
moss --versionVerify Fix Applied:
Verify version is 0.15+ and test that file upload restrictions are enforced📡 Detection & Monitoring
Log Indicators:
- Multiple file upload attempts with executable extensions
- Files uploaded to non-standard directories
- Large files uploaded in quick succession
Network Indicators:
- HTTP POST requests to upload endpoints with executable file types
- Unusual traffic patterns to upload functionality
SIEM Query:
source="moss.log" AND ("upload" OR "POST /upload") AND (ext="php" OR ext="jsp" OR ext="exe" OR ext="sh")