CVE-2020-37112: GUnet OpenEclass SQL Injection Vulnerability

CVE-2020-37112 Overview

GUnet OpenEclass 1.7.3 contains multiple SQL injection vulnerabilities that allow authenticated attackers to manipulate database queries through unvalidated parameters. Attackers can exploit the month parameter in the agenda module and other endpoints to extract sensitive database information using error-based or time-based injection techniques.

Critical Impact

Authenticated attackers can extract sensitive database information including user credentials, student records, and other educational data through SQL injection attacks on the e-learning platform.

Affected Products

• GUnet OpenEclass 1.7.3
• GUnet OpenEclass prior versions with vulnerable agenda module
• E-learning platforms using affected OpenEclass deployments

Discovery Timeline

• 2026-02-03 - CVE CVE-2020-37112 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2020-37112

Vulnerability Analysis

This SQL injection vulnerability (CWE-89) exists in GUnet OpenEclass 1.7.3 within the agenda module. The application fails to properly sanitize user-supplied input in the month parameter before incorporating it into SQL queries. This allows authenticated users to inject arbitrary SQL commands that the database server executes with the application's privileges.

The vulnerability can be exploited through both error-based and time-based blind SQL injection techniques. Error-based injection allows attackers to extract data through database error messages, while time-based blind injection enables data exfiltration by observing response time differences when conditional SQL statements are executed.

Root Cause

The root cause of this vulnerability is improper input validation and the failure to use parameterized queries or prepared statements. The month parameter in the agenda module is directly concatenated into SQL queries without sanitization, escaping, or type validation. This classic SQL injection flaw allows attackers to break out of the intended query structure and execute arbitrary SQL commands.

Attack Vector

The attack is network-based and requires authentication to the OpenEclass platform. Once authenticated, an attacker can craft malicious requests to the agenda module with specially crafted month parameter values. The injected SQL payload can be designed to:

1. Extract database schema information
2. Dump user credentials and personal data
3. Read sensitive student records and grades
4. Potentially modify or delete database contents
5. In some configurations, read files from the server or execute system commands

The vulnerability can be exploited using common SQL injection tools or manual injection techniques targeting the vulnerable endpoint.

Detection Methods for CVE-2020-37112

Indicators of Compromise

• Unusual SQL syntax patterns in HTTP request parameters, particularly the month parameter
• Database error messages appearing in application responses or logs
• Abnormal database query patterns with UNION SELECT, OR 1=1, or time-delay functions like SLEEP() or BENCHMARK()
• Unexpected database access from the web application user account

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in request parameters
• Monitor database query logs for anomalous queries containing SQL keywords in unexpected positions
• Deploy application-level logging to capture all requests to the agenda module endpoint
• Use database activity monitoring to detect data exfiltration attempts

Monitoring Recommendations

• Enable detailed logging for the OpenEclass agenda module and related endpoints
• Configure alerts for database errors that may indicate injection attempts
• Monitor for high-volume requests from authenticated users targeting parameter-based endpoints
• Review authentication logs for accounts making suspicious requests to vulnerable endpoints

How to Mitigate CVE-2020-37112

Immediate Actions Required

• Upgrade GUnet OpenEclass to a patched version that addresses the SQL injection vulnerabilities
• Implement input validation and parameterized queries if custom code modifications are necessary
• Deploy a Web Application Firewall with SQL injection detection rules as a temporary mitigation
• Review database permissions to ensure the application uses least-privilege database accounts

Patch Information

Refer to the official Open eClass Release Notes for information about security patches and version updates. The VulnCheck Advisory on SQL Injection provides additional technical details about this vulnerability. Technical exploitation details are documented in Exploit-DB #48163.

Workarounds

• Implement Web Application Firewall rules to filter SQL injection patterns in the month parameter
• Restrict access to the agenda module to trusted users only until patching is complete
• Add application-level input validation to enforce expected data types (e.g., numeric-only for month values)
• Consider disabling the vulnerable agenda module functionality if it is not critical to operations

# Example WAF rule configuration for ModSecurity
# Block common SQL injection patterns in month parameter
SecRule ARGS:month "@detectSQLi" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt detected in month parameter'"