CVE-2025-69397

Executive Summary

CVE-2025-69397 is a critical PHP Local File Inclusion (LFI) vulnerability affecting the ThemeREX Tint WordPress theme, version 1.7 and earlier. 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 achieving remote code execution if combined with file upload capabilities.

The CVSS score of 8.1 (High) reflects the ease of exploitation (no authentication required) and the high impact on confidentiality. No public proof-of-concept (PoC) or exploit code has been identified at this time, but the vulnerability is trivially exploitable with a crafted HTTP request.

Supply Chain & Package Security

This vulnerability resides in a WordPress theme, which is part of the broader WordPress ecosystem. The theme is distributed via ThemeREX’s own marketplace and potentially bundled with other plugins. Users are advised to verify the integrity of their theme files and ensure they are sourced from trusted channels. No known supply chain compromise has been reported, but the lack of a patch increases the risk of malicious actors distributing modified versions.

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 is the only affected component.
• 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 easy to exploit and can expose sensitive server files, including database credentials and configuration files.

Deep Dive & Mechanics

The vulnerability exists in the tint theme’s PHP code, likely within a template or include function that accepts user-supplied input (e.g., via a GET or POST parameter) to dynamically include a file. The code does not properly sanitize or validate the filename, allowing path traversal sequences (e.g., ../../) to escape the intended directory.

Example vulnerable code pattern:

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

An attacker can request:

http://target.com/wp-content/themes/tint/page.php?file=../../../../wp-config

This would include /var/www/html/wp-config.php (assuming the web root is /var/www/html).

The theme’s include or require statement lacks a whitelist or directory restriction, making it susceptible to LFI. Since the vulnerability is in a WordPress theme, it is triggered via the WordPress frontend, not through Apache or Nginx directly.

Vulnerable vs. Patched Code

Vulnerable Code (Tint <= 1.7):

<?php
// In some template file (e.g., header.php or custom page template)
$page = $_GET['page'];
include( get_template_directory() . '/includes/' . $page . '.php' );
?>

This code directly concatenates user input into the file path without sanitization.

Patched Code (Hypothetical):

<?php
$allowed_pages = array('home', 'about', 'contact');
$page = $_GET['page'];
if (in_array($page, $allowed_pages)) {
    include( get_template_directory() . '/includes/' . $page . '.php' );
} else {
    // Handle error or redirect
    wp_die('Invalid page.');
}
?>

The patched version uses a whitelist to restrict which files can be included, preventing path traversal.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install WordPress with the Tint theme (version 1.7) on a local server (e.g., using XAMPP or Docker).
2. Ensure the theme is activated.

Exploitation Steps:

1. Identify the vulnerable parameter (e.g., page, file, template). Common locations include theme options or shortcodes.
2. Craft a request to read sensitive files:

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

3. If the server returns the file content, the vulnerability is confirmed.
4. For advanced exploitation, attempt to include log files (e.g., /var/log/apache2/access.log) and inject PHP code via User-Agent headers to achieve remote code execution.

Example curl command:

curl -v "http://target.com/wp-content/themes/tint/page.php?page=../../../../wp-config"

Blue Team (Defensive)

Detection:

• Monitor web server logs for path traversal patterns (e.g., ../, %2e%2e%2f).
• Look for requests to theme files with unexpected parameters.
• Use WAF rules to block directory traversal attempts.

Hunting:

• Search for include or require statements in the theme’s PHP files that use $_GET, $_POST, or $_REQUEST without sanitization.
• Check for file inclusion attempts in access logs:

  grep -E '\.\./' /var/log/apache2/access.log
  

Indicators of Compromise (IOCs)

• File Paths: /wp-content/themes/tint/ (any PHP file within this directory)
• HTTP Request Patterns:
  • GET /wp-content/themes/tint/*.php?*file=*../*
  • GET /wp-content/themes/tint/*.php?*page=*../*
• Log Entries: Requests containing %2e%2e%2f or ../ in query parameters.
• Network Indicators: Outbound connections from the web server to external IPs (if RCE is achieved).

Detection Engineering

YARA Rule

rule CVE_2025_69397_LFI_Tint {
    meta:
        description = "Detects PHP Local File Inclusion in ThemeREX Tint theme"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-69397"
    strings:
        $s1 = "include(" nocase
        $s2 = "require(" nocase
        $s3 = "$_GET" nocase
        $s4 = "$_POST" nocase
        $s5 = "$_REQUEST" nocase
        $s6 = ".php" nocase
    condition:
        all of ($s1, $s2, $s3, $s4, $s5, $s6) and filesize < 100KB
}

Sigma Rule

title: CVE-2025-69397 - ThemeREX Tint LFI Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects path traversal attempts targeting the Tint theme
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 
            - '../'
            - '%2e%2e%2f'
            - '..\\'
        cs-uri-stem|contains: '/wp-content/themes/tint/'
    condition: selection
falsepositives:
    - Legitimate use of relative paths (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-69397 ThemeREX Tint LFI Attempt"; flow:to_server,established; content:"GET"; http_method; content:"/wp-content/themes/tint/"; http_uri; content:"../"; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Tint theme until a patch is available. Switch to a different theme.
2. Implement a Web Application Firewall (WAF) rule to block path traversal patterns (e.g., ../, %2e%2e%2f).
3. Restrict file permissions on sensitive files (e.g., wp-config.php should be readable only by the web server user).

Long-term Fix:

• Apply a patch from ThemeREX once released. If no patch is forthcoming, consider replacing the theme permanently.
• Conduct a code review of all custom themes to ensure input sanitization is applied to file inclusion functions.

Workaround:

• Add the following to .htaccess to block suspicious requests:

  RewriteEngine On
  RewriteCond %{QUERY_STRING} (\.\./|%2e%2e%2f) [NC]
  RewriteRule ^wp-content/themes/tint/ - [F,L]
  

Valters IT