CVE-2023-53922
📋 TL;DR
CVE-2023-53922 is a critical remote code execution vulnerability in TinyWebGallery v2.5 that allows unauthenticated attackers to upload malicious PHP files via the admin upload functionality. By uploading .phar files containing system commands and accessing their URLs, attackers can execute arbitrary code on the server. All users running TinyWebGallery v2.5 are affected.
💻 Affected Systems
- TinyWebGallery
📦 What is this software?
Tinywebgallery by Tinywebgallery
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise allowing attackers to execute arbitrary commands, steal data, install malware, pivot to other systems, or use the server for further attacks.
Likely Case
Attackers upload web shells to gain persistent access, deface websites, steal sensitive data, or use the server for cryptocurrency mining or DDoS attacks.
If Mitigated
With proper file upload restrictions and web application firewalls, exploitation attempts would be blocked, limiting impact to failed attack attempts.
🎯 Exploit Status
Exploit code is publicly available and requires minimal technical skill to execute. The attack can be automated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: http://www.tinywebgallery.com/
Restart Required: No
Instructions:
1. Check the TinyWebGallery website for security updates. 2. If no patch is available, consider migrating to alternative gallery software. 3. Apply all workarounds listed below immediately.
🔧 Temporary Workarounds
Restrict file upload extensions
allConfigure web server to block .phar and .php file uploads
# For Apache: Add to .htaccess
<FilesMatch "\.(phar|php)$">
Order Allow,Deny
Deny from all
</FilesMatch>
# For Nginx: Add to server block
location ~ \.(phar|php)$ {
deny all;
}
Disable admin upload functionality
linuxRemove or disable the vulnerable upload feature
# Remove or rename the upload script
mv /path/to/tinywebgallery/admin/upload.php /path/to/tinywebgallery/admin/upload.php.disabled
🧯 If You Can't Patch
- Implement strict file upload validation that only allows image file extensions (jpg, png, gif)
- Place the application behind a web application firewall (WAF) with file upload protection rules
🔍 How to Verify
Check if Vulnerable:
Check if running TinyWebGallery v2.5 by examining version files or configuration. Test if unauthenticated file upload of .phar files is possible.Check Version:
grep -r 'version\|Version' /path/to/tinywebgallery/ | grep -i '2\.5'Verify Fix Applied:
Attempt to upload a .phar file to the admin upload endpoint. If the upload is blocked or the file cannot be executed, the workaround is effective.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads to admin endpoints
- .phar or .php files being uploaded from unexpected IPs
- POST requests to upload.php with suspicious filenames
Network Indicators:
- HTTP POST requests to /admin/upload.php with .phar files
- Subsequent requests to uploaded .phar files
SIEM Query:
source="web_logs" AND (uri_path="/admin/upload.php" AND file_extension IN ("phar", "php"))