CVE-2026-3956: Weimai-Wetapp SQL Injection Vulnerability

CVE-2026-3956 Overview

A SQL Injection vulnerability has been identified in the xierongwkhd weimai-wetapp application, specifically within the getAdmins function of the Admin_AdminUserController.java file. This vulnerability allows attackers to manipulate the keyword argument to inject malicious SQL queries, potentially leading to unauthorized data access, modification, or deletion.

Critical Impact

Remote attackers with elevated privileges can exploit this SQL injection vulnerability to extract sensitive data, modify database contents, or potentially compromise the underlying database server through crafted SQL queries.

Affected Products

• xierongwkhd weimai-wetapp (up to commit 5fe9e8225be4f73f2c5087f134aff657bdf1c6f2)
• weimai-wetapp rolling release versions prior to fix

Discovery Timeline

• 2026-03-11 - CVE-2026-3956 published to NVD
• 2026-03-12 - Last updated in NVD database

Technical Details for CVE-2026-3956

Vulnerability Analysis

This SQL Injection vulnerability (CWE-74: Injection) affects the administrative functionality of the weimai-wetapp application, a WeChat-based application. The vulnerable code resides in the Java controller responsible for admin user management at the path source-code/src/main/java/com/moke/wp/wx_weimai/controller/admin/Admin_AdminUserController.java.

The vulnerability occurs because the keyword parameter passed to the getAdmins function is not properly sanitized or parameterized before being incorporated into SQL queries. This allows an attacker with administrative privileges to craft malicious input that escapes the intended query context and executes arbitrary SQL commands against the backend database.

The attack vector is network-based, meaning exploitation can occur remotely. While high privileges are required to access the vulnerable administrative endpoint, the exploit is publicly available, increasing the risk of exploitation in environments where this application is deployed.

Root Cause

The root cause of this vulnerability is the lack of proper input validation and sanitization on the keyword parameter in the getAdmins function. The application constructs SQL queries by directly concatenating user-supplied input rather than using parameterized queries (prepared statements), which is the industry-standard approach to preventing SQL injection attacks.

Attack Vector

The vulnerability is exploitable over the network by authenticated administrators. An attacker with valid administrative credentials can access the vulnerable endpoint and inject malicious SQL through the keyword parameter. The injection can be used to:

1. Extract sensitive information from the database (data exfiltration)
2. Modify or delete existing records (data manipulation)
3. Potentially execute administrative database operations
4. In some database configurations, achieve command execution on the underlying system

The attack requires no user interaction beyond the attacker's own actions, making it straightforward to exploit once administrative access is obtained. For detailed technical information about the vulnerability mechanics, see the GitHub Issue Discussion and the VulDB entry.

Detection Methods for CVE-2026-3956

Indicators of Compromise

• Unusual SQL syntax appearing in web application logs, particularly in requests to admin user management endpoints
• Requests to /admin/ endpoints containing suspicious characters such as single quotes ('), semicolons (;), or SQL keywords like UNION, SELECT, or DROP
• Database error messages exposed in application responses indicating SQL syntax errors
• Unexpected database queries or access patterns from the application service account

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block SQL injection patterns in the keyword parameter
• Monitor application logs for requests containing SQL injection payloads targeting the Admin_AdminUserController endpoint
• Deploy database activity monitoring to detect anomalous queries originating from the application
• Use intrusion detection systems (IDS) with SQL injection signature rules enabled

Monitoring Recommendations

• Enable detailed logging for all administrative controller endpoints in the weimai-wetapp application
• Configure alerts for database queries that deviate from expected patterns or execution times
• Monitor for authentication attempts followed by requests containing SQL metacharacters
• Implement runtime application self-protection (RASP) to detect and block injection attempts in real-time

How to Mitigate CVE-2026-3956

Immediate Actions Required

• Review access controls and restrict administrative access to trusted users only
• Implement a Web Application Firewall with SQL injection protection rules
• Monitor the weimai-wetapp GitHub repository for security updates
• Audit administrative user accounts for any unauthorized access or suspicious activity
• Consider temporarily disabling or restricting access to the vulnerable admin search functionality

Patch Information

As of the last update on 2026-03-12, no official patch has been released by the maintainers. The vulnerability was reported via a GitHub issue, but the project has not responded yet. Since weimai-wetapp follows a rolling release model, users should monitor the repository for commits that address this SQL injection issue in the Admin_AdminUserController.java file.

Workarounds

• Implement input validation at the application gateway level to filter SQL injection payloads from the keyword parameter
• Deploy a reverse proxy with SQL injection filtering capabilities in front of the application
• Restrict network access to administrative endpoints using IP allowlisting
• Apply the principle of least privilege to the database user account used by the application

# Example: Nginx WAF rule to block basic SQL injection attempts
# Add to your nginx.conf server block
location /admin/ {
    if ($args ~* "(union|select|insert|update|delete|drop|;|'|--)" ) {
        return 403;
    }
    # ... rest of your proxy configuration
}