CVE-2026-7002: SQL Injection in KLiK SocialMediaWebsite Private Message Handler

Executive Summary

CVE-2026-7002 is a SQL injection vulnerability affecting KLiK SocialMediaWebsite versions up to and including 1.0.1. The flaw exists in the Private Message Handler component, specifically in the file /includes/get_message_ajax.php, where the c_id parameter is not properly sanitized before being incorporated into a SQL query. A remote attacker can manipulate this parameter to execute arbitrary SQL commands against the underlying database. The vulnerability carries a CVSS score of 7.3 (High).

Vulnerability Overview

Affected Product

KLiK SocialMediaWebsite is an open-source PHP-based social media web application. Its Private Message system allows users to exchange direct messages, and the AJAX-based message retrieval endpoint (get_message_ajax.php) passes user-controlled input directly into a SQL query without sanitization.

Technical Analysis

Root Cause

The vulnerability is caused by improper neutralization of special elements used in a SQL command (CWE-89). The c_id parameter accepted by /includes/get_message_ajax.php is incorporated into a SQL query without parameterization or input sanitization. An attacker who can send an HTTP request to this endpoint can inject arbitrary SQL syntax.

Vulnerable Code Pattern

The affected endpoint accepts a c_id value (conversation ID) via an HTTP request and uses it to query the messages table:

// Simplified representation of the vulnerable pattern
$c_id = $_GET['c_id'];  // No sanitization
$query = "SELECT * FROM messages WHERE conversation_id = '$c_id'";
$result = mysqli_query($conn, $query);

Without parameterized queries or prepared statements, any SQL metacharacter embedded in c_id is interpreted by the database engine.

Exploitation

An attacker can inject SQL payload via the c_id parameter to:

GET /includes/get_message_ajax.php?c_id=1' OR '1'='1
GET /includes/get_message_ajax.php?c_id=1' UNION SELECT username,password,3,4 FROM users--
GET /includes/get_message_ajax.php?c_id=1'; DROP TABLE messages;--

Error-based and UNION-based injection techniques are viable given the typical query structure. Automated tools like sqlmap can fully exploit this endpoint:

sqlmap -u "http://target/includes/get_message_ajax.php?c_id=1" \
  --dbs --batch --level=3 --risk=2

Attack Vector

The attack is fully remote and does not require authentication if the endpoint is accessible without a session check. If authentication is required, a low-privileged user account is sufficient to exploit the flaw.

Impact Assessment

SQL injection in a social media platform's private message system is particularly sensitive because it exposes private user communications in addition to standard account data — creating significant privacy and regulatory exposure (GDPR, PIPEDA, CCPA).

Remediation

Step 1: Apply Parameterized Queries

Replace all direct string interpolation in SQL queries with prepared statements using PDO or MySQLi:

// Secure implementation using PDO prepared statements
$stmt = $pdo->prepare("SELECT * FROM messages WHERE conversation_id = ?");
$stmt->execute([$c_id]);
$result = $stmt->fetchAll();

// Secure implementation using MySQLi prepared statements
$stmt = $conn->prepare("SELECT * FROM messages WHERE conversation_id = ?");
$stmt->bind_param("i", $c_id);
$stmt->execute();
$result = $stmt->get_result();

Step 2: Validate and Sanitize Input

Even with prepared statements, validate that c_id conforms to expected format:

// Input validation — c_id should be a positive integer
$c_id = filter_input(INPUT_GET, 'c_id', FILTER_VALIDATE_INT);
if ($c_id === false || $c_id === null || $c_id <= 0) {
    http_response_code(400);
    exit('Invalid request');
}

Step 3: Enforce Authentication Checks

Verify that get_message_ajax.php requires an active authenticated session before processing any requests:

session_start();
if (!isset($_SESSION['user_id'])) {
    http_response_code(403);
    exit('Unauthorized');
}

Step 4: Apply Least-Privilege Database Permissions

The MySQL user used by the application should only have the minimum necessary permissions:

-- Grant only SELECT, INSERT, UPDATE, DELETE — never FILE or SUPER
GRANT SELECT, INSERT, UPDATE, DELETE ON klik_db.* TO 'klik_user'@'localhost';
REVOKE ALL PRIVILEGES ON *.* FROM 'klik_user'@'localhost';

Step 5: Deploy a Web Application Firewall

As an additional defense layer, configure WAF rules to detect and block SQL injection patterns against AJAX endpoints.

Detection Indicators

MySQL Query Log Monitoring

# Enable general query log to capture injection attempts
SET GLOBAL general_log = 'ON';
SET GLOBAL general_log_file = '/var/log/mysql/general.log';
 
# Review for suspicious patterns
grep -i "union\|select.*from\|drop\|insert into" /var/log/mysql/general.log

Post-Remediation Checklist

1. Apply prepared statements to all SQL queries in get_message_ajax.php and audit all other PHP files for similar patterns
2. Validate all user-controlled parameters with appropriate type checking and whitelisting
3. Audit database access logs for signs of prior exploitation
4. Rotate all user credentials stored in the application database
5. Review private message data for unauthorized access evidence
6. Restrict database user permissions to least-privilege
7. Deploy WAF rules for SQLi pattern detection
8. Notify affected users if there is evidence that private message or credential data was accessed

References

• NVD — CVE-2026-7002
• CWE-89: Improper Neutralization of Special Elements used in an SQL Command
• OWASP SQL Injection Prevention Cheat Sheet