CVE-2020-37147: ATutor SQL Injection Vulnerability

CVE-2020-37147 Overview

ATutor 2.2.4 contains a SQL injection vulnerability in the admin user deletion page that allows authenticated attackers to manipulate database queries through the id parameter. Attackers can exploit the vulnerability by injecting malicious SQL code into the id parameter of the admin_delete.php script to potentially extract or modify database information.

Critical Impact

Authenticated attackers with admin privileges can exploit this SQL injection flaw to extract sensitive database information or modify database records, potentially compromising the entire ATutor learning management system.

Affected Products

• ATutor 2.2.4

Discovery Timeline

• 2026-02-07 - CVE CVE-2020-37147 published to NVD
• 2026-02-09 - Last updated in NVD database

Technical Details for CVE-2020-37147

Vulnerability Analysis

This vulnerability is classified as CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), commonly known as SQL Injection. The flaw exists in the admin user deletion functionality of ATutor, specifically within the admin_delete.php script. When an authenticated administrator attempts to delete a user, the application fails to properly sanitize the id parameter before incorporating it into SQL queries.

The network-accessible attack vector means that exploitation can occur remotely without requiring physical access to the target system. While the vulnerability does require high privileges (administrative access) to exploit, the lack of user interaction needed and the low attack complexity make this a significant security concern for ATutor deployments.

Root Cause

The root cause of this vulnerability is inadequate input validation and the absence of parameterized queries in the admin_delete.php script. The application directly concatenates user-supplied input from the id parameter into SQL statements without proper sanitization or the use of prepared statements, allowing attackers to inject arbitrary SQL commands.

Attack Vector

An authenticated attacker with administrative privileges can craft malicious HTTP requests to the admin_delete.php endpoint with a manipulated id parameter. By injecting SQL syntax into this parameter, the attacker can modify the intended query logic to perform unauthorized database operations.

The attack is network-based, meaning exploitation occurs over HTTP/HTTPS connections to the vulnerable ATutor installation. The attacker must first authenticate as an administrator, then send crafted requests containing SQL injection payloads in the id parameter. Successful exploitation could allow extraction of sensitive data from the database, modification of existing records, or potentially gaining further access to the underlying system depending on database configuration and privileges.

Detection Methods for CVE-2020-37147

Indicators of Compromise

• Unusual or malformed requests to the admin_delete.php endpoint containing SQL syntax characters such as single quotes, semicolons, or SQL keywords
• Database error messages appearing in application logs or HTTP responses indicating SQL syntax errors
• Unexpected database query patterns or access to tables beyond normal administrative operations
• Audit logs showing administrative deletion requests with abnormally long or encoded id parameter values

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in requests to ATutor admin pages
• Monitor HTTP request logs for suspicious patterns in the id parameter, including SQL keywords like UNION, SELECT, DROP, or comment sequences
• Deploy database activity monitoring to identify anomalous query patterns or unauthorized data access
• Review application logs for SQL error messages that may indicate injection attempts

Monitoring Recommendations

• Enable detailed logging for all requests to administrative endpoints in ATutor
• Configure alerting for database errors or exceptions originating from the admin_delete.php script
• Implement integrity monitoring on critical database tables to detect unauthorized modifications
• Establish baseline behavior for administrative actions to identify anomalous deletion patterns

How to Mitigate CVE-2020-37147

Immediate Actions Required

• Restrict network access to the ATutor administrative interface to trusted IP addresses only
• Implement additional authentication controls such as multi-factor authentication for admin accounts
• Deploy a Web Application Firewall with SQL injection protection rules in front of the ATutor installation
• Review administrative user accounts and remove any unnecessary or suspicious admin privileges

Patch Information

Organizations running ATutor 2.2.4 should check the ATutor Project for any available security updates or patches addressing this vulnerability. Additional technical details about this vulnerability can be found in the VulnCheck ATutor SQL Injection Advisory and Exploit-DB #48117.

Workarounds

• Implement input validation at the web server or reverse proxy level to sanitize the id parameter before it reaches the application
• Deploy network segmentation to limit database access from the web application tier
• Consider temporarily disabling the admin user deletion functionality if it is not business-critical until a patch is available
• Apply virtual patching through WAF rules specifically targeting SQL injection in the admin_delete.php endpoint

# Example WAF rule (ModSecurity) to block SQL injection in id parameter
SecRule ARGS:id "@detectSQLi" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    msg:'SQL Injection attempt detected in id parameter',\
    log,\
    auditlog"