CVE-2020-37141: AMSS++ SQL Injection Vulnerability

CVE-2020-37141 Overview

CVE-2020-37141 is a SQL Injection vulnerability affecting AMSS++ version 4.31. The vulnerability exists in the mail module's maildetail.php script, which fails to properly sanitize user input passed through the id parameter. Attackers can exploit this flaw by injecting malicious SQL queries via the /modules/mail/main/maildetail.php endpoint to potentially access or modify database contents.

Critical Impact

This SQL injection vulnerability enables unauthenticated attackers to read sensitive database information and potentially modify data, compromising the confidentiality and integrity of the affected system.

Affected Products

• AMSS++ version 4.31

Discovery Timeline

• 2026-02-07 - CVE CVE-2020-37141 published to NVD
• 2026-02-09 - Last updated in NVD database

Technical Details for CVE-2020-37141

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) occurs in the maildetail.php script within the mail module of AMSS++. The script accepts a user-controlled id parameter without adequate input validation or sanitization before incorporating it into SQL queries. This classic injection pattern allows attackers to break out of the intended SQL query structure and execute arbitrary database commands.

The vulnerability is network-accessible, meaning remote attackers can exploit it without requiring any prior authentication or special privileges. Successful exploitation could lead to unauthorized data disclosure, data manipulation, or in some cases, complete database compromise depending on the database user's privileges.

Root Cause

The root cause is improper input validation (CWE-89: Improper Neutralization of Special Elements used in an SQL Command). The maildetail.php script directly concatenates the user-supplied id parameter into SQL queries without proper sanitization, parameterized queries, or prepared statements. This allows special SQL characters and syntax to be interpreted as part of the query structure rather than as literal data values.

Attack Vector

The attack vector is network-based, targeting the /modules/mail/main/maildetail.php endpoint. An attacker crafts a malicious request with SQL injection payloads in the id parameter. The vulnerable script processes this input and executes the injected SQL commands against the backend database.

Typical exploitation involves:

1. Identifying the vulnerable endpoint and parameter
2. Testing for SQL injection using common techniques (single quotes, boolean-based, union-based, or time-based blind injection)
3. Extracting database schema information
4. Dumping sensitive data from database tables

For detailed technical information, refer to the VulnCheck Advisory and Exploit-DB #48109.

Detection Methods for CVE-2020-37141

Indicators of Compromise

• HTTP requests to /modules/mail/main/maildetail.php containing SQL injection patterns such as single quotes, double dashes, UNION SELECT statements, or time-based injection keywords
• Unusual database query errors in application logs originating from the mail module
• Database audit logs showing unexpected queries or access to sensitive tables from the AMSS++ application
• Anomalous outbound traffic from the database server potentially indicating data exfiltration

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL injection attempts targeting the id parameter
• Enable application-level logging for the mail module to capture and analyze requests to maildetail.php
• Implement database query monitoring to detect anomalous or malformed SQL statements
• Use intrusion detection systems (IDS) with SQL injection signature detection capabilities

Monitoring Recommendations

• Monitor web server access logs for suspicious requests to /modules/mail/main/maildetail.php with unusual id parameter values
• Configure database audit logging to track all queries executed against the AMSS++ database
• Set up alerts for database errors or exceptions that may indicate injection attempts
• Implement real-time security monitoring for pattern-based detection of SQL injection attacks

How to Mitigate CVE-2020-37141

Immediate Actions Required

• Restrict network access to the AMSS++ application to trusted IP addresses only until a patch can be applied
• Implement WAF rules to filter SQL injection attempts targeting the vulnerable endpoint
• Review database user privileges and apply the principle of least privilege to limit potential damage
• Consider disabling or restricting access to the mail module if not critical to operations

Patch Information

Consult the AMSS++ vendor for official security patches addressing this vulnerability. Review the VulnCheck Advisory for the latest remediation guidance.

Workarounds

• Deploy a Web Application Firewall (WAF) with SQL injection protection rules in front of the AMSS++ application
• Implement input validation at the web server level to sanitize the id parameter before it reaches the application
• Use network segmentation to isolate the AMSS++ server and limit access to trusted networks
• Apply database-level controls such as stored procedure restrictions and query parameterization where possible

# Example WAF rule configuration (ModSecurity)
# Block SQL injection attempts on maildetail.php
SecRule REQUEST_URI "@contains /modules/mail/main/maildetail.php" \
    "id:1001,phase:2,deny,status:403,\
    chain,msg:'SQL Injection attempt detected on maildetail.php'"
SecRule ARGS:id "@detectSQLi" "t:none"