CVE-2025-48290

Executive Summary

CVE-2025-48290 is a critical PHP Local File Inclusion (LFI) vulnerability discovered in the Kinsley WordPress theme developed by bslthemes. The vulnerability stems from improper control of a filename used in a PHP include or require statement, allowing an unauthenticated attacker to include arbitrary local files from the server. This can lead to sensitive information disclosure, such as reading the wp-config.php file containing database credentials, or potentially escalating to remote code execution if combined with file upload capabilities. The vulnerability affects all versions of Kinsley up to and including 3.4.4. No official patch has been released at this time, and no public proof-of-concept (PoC) code is available.

Supply Chain & Package Security

This vulnerability affects a WordPress theme distributed through the official WordPress theme repository and potentially via third-party marketplaces. Users who have installed the Kinsley theme are at risk. Since the theme is a PHP-based component of the WordPress ecosystem, the attack surface is limited to WordPress installations running the vulnerable theme. No supply chain compromise of the theme's source code repository has been reported.

CVSS Breakdown & Threat Level

CVSS Score: 8.1 (High) Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

• Attack Vector (AV): Network – The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low – No special conditions or complex attack sequences are required.
• Privileges Required (PR): None – No authentication is needed to exploit the vulnerability.
• User Interaction (UI): None – The victim does not need to perform any action.
• Scope (S): Unchanged – The vulnerable component and the impacted component are the same.
• Confidentiality (C): High – An attacker can read sensitive files from the server.
• Integrity (I): None – The vulnerability does not allow modification of data.
• Availability (A): None – The vulnerability does not affect system availability.

Threat Level: High. The low attack complexity and lack of required privileges make this a serious threat for any WordPress site using the Kinsley theme.

Deep Dive & Mechanics

The vulnerability is a classic PHP Local File Inclusion (LFI) issue, categorized under CWE-98: Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion'). The Kinsley theme likely uses a dynamic include or require statement that takes a user-supplied parameter (e.g., via $_GET, $_POST, or a cookie) to load a template or module file. If the input is not properly sanitized or validated, an attacker can manipulate the path to include arbitrary files from the server.

For example, a vulnerable code snippet might look like:

$template = $_GET['template'];
include("templates/" . $template . ".php");

An attacker could supply a path like ../../../../etc/passwd%00 to read the /etc/passwd file (null byte injection) or use directory traversal to include sensitive files. Since the vulnerability is in a WordPress theme, the most common target is the wp-config.php file, which contains database credentials and authentication keys.

The attack is performed by sending a crafted HTTP request to the WordPress site with a malicious parameter value. The server then includes the specified file, outputting its contents to the attacker.

Vulnerable vs. Patched Code

Since no official patch is available, the following is a hypothetical comparison based on common LFI fixes.

Vulnerable Code (Kinsley <= 3.4.4):

// Example vulnerable function in a theme template loader
function kinsley_load_template() {
    $template = $_GET['template'];
    include( get_template_directory() . '/templates/' . $template . '.php' );
}

Patched Code (Hypothetical):

function kinsley_load_template() {
    // Whitelist allowed templates
    $allowed_templates = array('header', 'footer', 'sidebar', 'content');
    $template = $_GET['template'];
    if ( in_array( $template, $allowed_templates ) ) {
        include( get_template_directory() . '/templates/' . $template . '.php' );
    } else {
        // Default to a safe template or error
        include( get_template_directory() . '/templates/error.php' );
    }
}

The patched version uses a whitelist approach to ensure only predefined template names can be included, preventing directory traversal and arbitrary file inclusion.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install a local WordPress instance (e.g., using Docker or XAMPP).
2. Install the Kinsley theme version 3.4.4 or earlier.
3. Identify the vulnerable parameter by analyzing the theme's source code (look for include, require, file_get_contents with user input).

Exploitation Steps:

1. Send a crafted HTTP request to the WordPress site:

   GET /?template=../../../../wp-config.php HTTP/1.1
   Host: target-wordpress-site.com
   

2. If the vulnerability is present, the server will return the contents of wp-config.php in the response.
3. For more advanced exploitation, attempt to include log files (e.g., /var/log/apache2/access.log) and inject PHP code into the logs via the User-Agent header, then include the log file to achieve Remote Code Execution (RCE).

Example curl command:

curl -v "http://target-wordpress-site.com/?template=../../../../wp-config.php"

Blue Team (Defensive)

Detection:

• Monitor web server logs for suspicious template parameter values containing directory traversal sequences (../, ..\\, %2e%2e%2f).
• Look for requests attempting to include sensitive files like wp-config.php, /etc/passwd, or /proc/self/environ.
• Use Web Application Firewall (WAF) rules to block requests with path traversal patterns.

Mitigation:

• Immediately update the Kinsley theme if a patch becomes available.
• If no patch is available, consider disabling or replacing the theme.
• Implement a WAF rule to block LFI attempts:

  # Apache mod_rewrite rule to block LFI
  RewriteCond %{QUERY_STRING} (\.\./|\.\.\\) [NC]
  RewriteRule .* - [F,L]
  

• Apply input validation and sanitization at the application level (e.g., whitelist allowed template names).

Indicators of Compromise (IOCs)

• File Paths: /wp-content/themes/kinsley/ (vulnerable theme directory)
• HTTP Request Patterns:
  • GET /?template=../../../../wp-config.php
  • GET /?template=../../../../etc/passwd
  • GET /?template=php://filter/convert.base64-encode/resource=wp-config.php
• Log Entries: Web server logs showing 404 or 200 responses for requests with template parameter containing ../ or ..\\.
• Network Indicators: Outbound connections from the web server to attacker-controlled IPs (if RCE is achieved).

Detection Engineering

YARA Rule

rule CVE_2025_48290_Kinsley_LFI {
    meta:
        description = "Detects attempts to exploit CVE-2025-48290 in Kinsley WordPress theme"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-48290"
    strings:
        $traversal1 = "../"
        $traversal2 = "..\\"
        $traversal3 = "%2e%2e%2f"
        $traversal4 = "%2e%2e%5c"
        $sensitive1 = "wp-config.php"
        $sensitive2 = "/etc/passwd"
        $sensitive3 = "/proc/self/environ"
    condition:
        any of ($traversal*) and any of ($sensitive*)
}

Sigma Rule

title: CVE-2025-48290 Kinsley LFI Detection
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects HTTP requests attempting to exploit LFI in Kinsley theme
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - 'template='
            - '../'
            - '..\\'
            - '%2e%2e%2f'
            - '%2e%2e%5c'
            - 'wp-config.php'
            - '/etc/passwd'
    condition: selection
falsepositives:
    - Legitimate use of template parameter with valid paths
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-48290 Kinsley LFI Attempt"; flow:to_server,established; content:"GET"; http_method; content:"template="; http_uri; content:"../"; http_uri; distance:0; content:"wp-config.php"; http_uri; distance:0; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: If you are using the Kinsley theme version 3.4.4 or earlier, disable the theme immediately and switch to a different, actively maintained theme.
2. Patch: Monitor the official bslthemes website or WordPress theme repository for a security update. Apply the patch as soon as it becomes available.
3. Workaround: If you cannot disable the theme, implement a Web Application Firewall (WAF) rule to block directory traversal patterns in the template parameter.
4. Code Fix: If you have access to the theme source code, apply input validation by whitelisting allowed template names (as shown in the patched code example).
5. Monitoring: Enable detailed logging for web server requests and review logs for suspicious activity. Use the provided YARA, Sigma, and Suricata rules to detect exploitation attempts.
6. Hardening: Ensure the WordPress installation is up to date and follow security best practices, such as using strong database credentials and limiting file permissions.

Valters IT
Securing Digital Frontiers