CVE-2020-25733
📋 TL;DR
CVE-2020-25733 is an unrestricted file upload vulnerability in webTareas that allows attackers to upload dangerous .exe and .shtml files. This can lead to remote code execution or server-side includes execution. All webTareas users through version 2.1 are affected.
💻 Affected Systems
- webTareas
📦 What is this software?
Webtareas by Webtareas Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, and lateral movement within the network.
Likely Case
Attackers upload malicious files to execute arbitrary code, deface websites, or establish persistent backdoors.
If Mitigated
If proper file type validation is implemented, only authorized file types can be uploaded, preventing exploitation.
🎯 Exploit Status
Exploitation requires authentication to access file upload functionality. The vulnerability is simple to exploit once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://sourceforge.net/p/webtareas/tickets/40/
Restart Required: No
Instructions:
No official patch exists. Consider upgrading to a different task management solution or implementing workarounds.
🔧 Temporary Workarounds
Web Server File Type Restriction
allConfigure web server to block .exe and .shtml file uploads at the server level
# Apache: Add to .htaccess or virtual host config
<FilesMatch "\.(exe|shtml)$">
Order Allow,Deny
Deny from all
</FilesMatch>
# Nginx: Add to server block
location ~ \.(exe|shtml)$ {
deny all;
}
Application Layer Filtering
allModify webTareas source code to validate file extensions before upload
# Add to upload handling PHP code
$allowed_extensions = array('jpg', 'png', 'pdf', 'txt');
$file_extension = strtolower(pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION));
if (!in_array($file_extension, $allowed_extensions)) {
die('Invalid file type');
}
🧯 If You Can't Patch
- Implement network segmentation to isolate webTareas instances from critical systems
- Deploy web application firewall with file upload protection rules
🔍 How to Verify
Check if Vulnerable:
Attempt to upload .exe or .shtml file through webTareas interface. If successful, system is vulnerable.Check Version:
Check webTareas version in admin panel or read CHANGELOG.txt file in installation directoryVerify Fix Applied:
Attempt to upload .exe or .shtml file. Upload should be rejected with error message.📡 Detection & Monitoring
Log Indicators:
- Successful uploads of .exe or .shtml files in web server access logs
- Unusual file upload patterns or large number of upload attempts
Network Indicators:
- HTTP POST requests to upload endpoints with executable file extensions
- Unusual outbound connections from web server after file uploads
SIEM Query:
source="web_server_logs" AND (uri_path="*upload*" OR uri_path="*file*" OR method="POST") AND (file_extension=".exe" OR file_extension=".shtml")🔗 References
- https://medium.com/%40tehwinsam/webtareas-2-1-c8b406c68c2a
- https://sourceforge.net/p/webtareas/tickets/40/
- https://sourceforge.net/projects/webtareas/files/
- https://medium.com/%40tehwinsam/webtareas-2-1-c8b406c68c2a
- https://sourceforge.net/p/webtareas/tickets/40/
- https://sourceforge.net/projects/webtareas/files/
