CVE-2025-69407

Executive Summary

CVE-2025-69407 is a critical PHP Local File Inclusion (LFI) vulnerability affecting the Struktur WordPress theme by Select-Themes, up to and including version 2.5.1. The vulnerability stems from improper control of a filename used in a PHP 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 /etc/passwd, configuration files, or WordPress wp-config.php. The CVSS score of 8.1 reflects the high impact on confidentiality with low attack complexity and no required privileges. As a WordPress ecosystem issue, this vulnerability is particularly dangerous because it can be exploited via the web interface without authentication. No public exploit code or patch is currently available, making proactive detection and mitigation essential.

Supply Chain & Package Security

This vulnerability is specific to the Struktur WordPress theme, which is distributed via the WordPress theme repository and third-party marketplaces. Users should verify the integrity of their theme files and monitor for official updates from Select-Themes. Since the patch status is unknown, organizations using this theme should consider it a supply chain risk and evaluate alternative themes or implement virtual patching.

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: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: None
• Availability Impact: None

The threat level is High due to the ease of exploitation (no authentication required) and the potential for sensitive data exposure. The EPSS score of 0.0% suggests low exploitation activity currently, but this may change as awareness increases.

Deep Dive & Mechanics

The vulnerability exists in the Struktur theme's PHP code, where a user-supplied parameter (likely via $_GET or $_POST) is used directly in a PHP include() or require() statement without proper sanitization or validation. For example, a vulnerable code snippet might look like:

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

An attacker can manipulate the file parameter to include arbitrary files by using path traversal sequences (e.g., ../../../../etc/passwd%00) to null-terminate the appended .php extension or by using PHP wrappers like php://filter to read source code.

The attack flow:

1. Attacker identifies a vulnerable endpoint in the theme (e.g., /?file=...).
2. Attacker sends a crafted request with path traversal to include a sensitive file.
3. The server includes the file, outputting its contents in the HTTP response.

Vulnerable vs. Patched Code

Vulnerable Code (<= 2.5.1):

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

Patched Code (Hypothetical):

// patched.php
$allowed_files = array('home', 'about', 'contact');
$file = $_GET['file'];
if (in_array($file, $allowed_files)) {
    include($file . '.php');
} else {
    // error handling
}

The patched version uses a whitelist approach to restrict included files to a predefined set, preventing arbitrary file inclusion.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress installation with the Struktur theme (<= 2.5.1) active.
• Knowledge of the vulnerable parameter (e.g., file, template, page).

Exploitation Steps:

1. Identify the vulnerable parameter by fuzzing the theme's endpoints.
2. Use path traversal to read sensitive files:

   curl "http://target.com/?file=../../../../etc/passwd%00"
   

3. Use PHP wrappers to read source code:

   curl "http://target.com/?file=php://filter/convert.base64-encode/resource=wp-config"
   

4. Decode the base64 output to retrieve credentials.

Lab Setup:

• Use Docker to deploy a vulnerable WordPress instance:

  docker run -d --name wp-vuln -p 8080:80 wordpress:latest
  # Manually install Struktur theme <= 2.5.1
  

Blue Team (Defensive)

Detection:

• Monitor web server logs for suspicious file parameters containing ../, %00, or php://.
• Deploy WAF rules to block path traversal and PHP wrapper usage.

Hunting:

• Search for requests with file= followed by directory traversal patterns.
• Look for base64-encoded strings in HTTP responses.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests containing file=../../../../etc/passwd
  • HTTP requests containing file=php://filter/
  • HTTP responses with base64-encoded content or sensitive file contents.

• File System IOCs:

  • Unexpected inclusion of files like /etc/passwd, /etc/shadow, or wp-config.php in web server logs.
  • Presence of temporary files created by exploitation attempts.

• Log IOCs:

  • Apache/Nginx access logs showing GET /?file=... with path traversal sequences.
  • PHP error logs indicating failed include attempts.

Detection Engineering

YARA Rule

rule CVE_2025_69407_LFI_Struktur {
    meta:
        description = "Detects LFI attempts targeting Struktur theme CVE-2025-69407"
        author = "Valters IT"
        date = "2025-04-10"
        severity = "high"
    strings:
        $path_traversal = /file=[^&]*\.\.\//
        $php_wrapper = /file=php:\/\//
        $null_byte = /file=[^&]*%00/
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-69407 LFI Attempt on Struktur Theme
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects HTTP requests with path traversal or PHP wrapper in file parameter
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - 'file=../'
            - 'file=php://'
            - 'file=%00'
    condition: selection
falsepositives:
    - Legitimate use of file parameters in other contexts
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-69407 LFI Attempt on Struktur Theme"; flow:to_server,established; content:"file="; nocase; http_uri; pcre:"/file=[^&]*\.\.\//i"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Actions:

   • Disable or remove the Struktur theme until a patch is available.
   • Implement a Web Application Firewall (WAF) rule to block file parameters containing ../, php://, or %00.
   • Restrict file inclusion to a whitelist of allowed files.

2. Long-term Fix:

   • Apply the official patch from Select-Themes when released.
   • Replace the theme with a secure alternative.

3. Compensating Controls:

   • Enable open_basedir in PHP to restrict file access.
   • Disable allow_url_include and allow_url_fopen if not needed.
   • Monitor logs for exploitation attempts.

4. Validation:

   • After applying mitigations, test the endpoint with path traversal payloads to confirm blocking.

Valters IT
Securing Digital Frontiers