CVE-2020-37090 Overview
School ERP Pro 1.0 contains a critical file upload vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) that allows authenticated students to upload arbitrary PHP files through the messaging system. Attackers can exploit the message attachment feature to upload malicious PHP scripts, enabling remote code execution on the server.
Critical Impact
This vulnerability allows low-privileged users (students) to achieve remote code execution on the web server by uploading malicious PHP files through the messaging attachment feature, potentially compromising the entire school management system and sensitive student data.
Affected Products
- School ERP Pro 1.0
Discovery Timeline
- 2026-02-03 - CVE CVE-2020-37090 published to NVD
- 2026-02-04 - Last updated in NVD database
Technical Details for CVE-2020-37090
Vulnerability Analysis
The vulnerability resides in School ERP Pro's messaging system, specifically in the file attachment handling functionality. The application fails to properly validate the file type and content of attachments uploaded through the messaging feature. This allows authenticated users, including those with low privileges such as students, to bypass intended file type restrictions and upload arbitrary PHP files.
Once a malicious PHP file is uploaded to the server, the attacker can directly access the uploaded file via a predictable or discoverable URL path, causing the web server to execute the PHP code. This grants the attacker the ability to run arbitrary commands on the underlying server with the privileges of the web server process.
The vulnerability is particularly severe in educational environments where student accounts are widely distributed and may be compromised or misused.
Root Cause
The root cause is improper input validation (CWE-434) in the file upload handling code within the messaging module. The application does not implement sufficient server-side validation to restrict file uploads to safe file types. Key deficiencies include:
- No server-side validation of file extensions
- Missing MIME type verification
- Absence of content-type inspection
- No restrictions on executable file types like .php, .phtml, or .php5
Attack Vector
The attack is network-based and requires low privileges (an authenticated student account). The attacker follows this exploitation path:
- Authenticate to the School ERP Pro application using valid student credentials
- Navigate to the messaging system's attachment upload feature
- Craft a malicious PHP file containing web shell code or command execution payloads
- Upload the PHP file as a message attachment, bypassing client-side restrictions
- Locate the uploaded file path on the server (typically in a predictable uploads directory)
- Access the uploaded PHP file directly via HTTP, triggering code execution
- Execute arbitrary commands on the server
The vulnerability mechanism involves the server accepting and storing the uploaded PHP file without sanitization, then serving it in a way that allows PHP execution. For detailed technical information, refer to the Exploit-DB #48392 and the VulnCheck Remote Code Execution Advisory.
Detection Methods for CVE-2020-37090
Indicators of Compromise
- Presence of unexpected .php, .phtml, or .php5 files in message attachment upload directories
- Web server access logs showing direct requests to uploaded files in attachment folders
- Unusual file creation timestamps in upload directories during non-business hours
- Web shell signatures or command execution patterns in uploaded file contents
Detection Strategies
- Monitor web server logs for POST requests to message attachment upload endpoints followed by GET requests to the same uploaded file
- Implement file integrity monitoring on upload directories to detect new PHP file creation
- Deploy web application firewall (WAF) rules to detect file upload attacks targeting PHP extensions
- Review application logs for unusual attachment upload activity from student accounts
Monitoring Recommendations
- Configure alerts for any PHP file writes to the messaging attachment directories
- Monitor outbound connections from the web server that may indicate post-exploitation activity
- Implement real-time log analysis for suspicious URL patterns accessing upload directories
- Track student account activity for anomalous messaging behavior or high-volume attachments
How to Mitigate CVE-2020-37090
Immediate Actions Required
- Restrict or disable the file attachment feature in the messaging system until a patch is applied
- Implement server-side file type validation to block PHP and other executable file extensions
- Configure the web server to prevent PHP execution in upload directories
- Audit existing uploaded files in the attachment directory for malicious content
- Consider migrating to a supported and actively maintained school management solution
Patch Information
No official vendor patch has been identified in the available CVE data. The original vendor (Arox) and the SourceForge project appear to be archived based on the Arox Website Archive and SourceForge Project Archive. Organizations using School ERP Pro 1.0 should implement workarounds immediately and consider migrating to an actively maintained alternative.
Workarounds
- Add .htaccess rules or web server configuration to disable PHP execution in upload directories
- Implement a whitelist of allowed file extensions (e.g., .pdf, .doc, .jpg, .png) at the server level
- Store uploaded files outside the web root and serve them through a download script that sets appropriate headers
- Apply network segmentation to limit the blast radius if the web server is compromised
# Apache configuration to disable PHP execution in upload directories
# Add to .htaccess or httpd.conf for the uploads directory
<Directory "/var/www/html/school-erp/uploads">
php_admin_flag engine off
AddHandler default-handler .php .phtml .php5
</Directory>
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
