CVE-2025-68544

Executive Summary

CVE-2025-68544 is a critical PHP Local File Inclusion (LFI) vulnerability discovered in the Diza WordPress theme developed by Thembay. 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 vulnerability affects all versions of Diza up to and including 1.3.15. No official patch has been released at the time of this report.

WordPress Ecosystem Context

This vulnerability is specific to the Diza WordPress theme. It is not a server-level issue (Apache/Nginx) but a flaw in the theme's PHP code. Attackers can exploit this by crafting a malicious HTTP request that manipulates a file path parameter, leading to the inclusion of arbitrary files from the WordPress installation.

CVSS Breakdown & Threat Level

• CVSS Score: 7.5 (High)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: None (I:N)
• Availability Impact: None (A:N)

The high confidentiality impact makes this a serious threat, as it can expose sensitive configuration files and database credentials.

Deep Dive & Mechanics

The vulnerability exists in the Diza theme's PHP code where a filename parameter is passed to an include() or require() function without proper sanitization or validation. The typical vulnerable pattern is:

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

An attacker can manipulate the file parameter to traverse directories using ../ sequences and include arbitrary files. For example:

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

This would include the wp-config.php file (without the .php extension, as it is appended automatically). The attacker can then read the contents of the file, revealing database credentials, salts, and other sensitive data.

The vulnerability is classified as CWE-98: Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion'), though in this case it is limited to local file inclusion due to the allow_url_include PHP directive being typically disabled.

Vulnerable vs. Patched Code

Vulnerable Code (Diza <= 1.3.15):

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

Patched Code (Hypothetical):

<?php
// patched-page.php
$allowed_files = array('home', 'about', 'contact');
$file = $_GET['file'];
if (in_array($file, $allowed_files)) {
    include($file . '.php');
} else {
    // Handle error
    echo 'Invalid file.';
}
?>

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

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress installation with Diza theme version <= 1.3.15
• Knowledge of the vulnerable endpoint (e.g., /wp-content/themes/diza/vulnerable-page.php)

Exploitation Steps:

1. Identify the vulnerable parameter: Use a web fuzzer or manual inspection to find a parameter that controls file inclusion (e.g., file, page, template).

2. Craft the payload: Use directory traversal to read sensitive files.

   curl "http://target.com/wp-content/themes/diza/vulnerable-page.php?file=../../../../wp-config"
   

3. Extract data: The response will contain the contents of wp-config.php.

4. Advanced exploitation: If the server has file upload capabilities (e.g., via a plugin), an attacker could upload a malicious PHP file (e.g., as an image) and then include it to achieve remote code execution.

   # Upload a PHP shell via a vulnerable upload endpoint
   curl -F "file=@shell.php" http://target.com/wp-content/plugins/vulnerable-upload/upload.php
   # Then include it
   curl "http://target.com/wp-content/themes/diza/vulnerable-page.php?file=../../../../wp-content/uploads/2025/01/shell"
   

Blue Team (Defensive)

Detection and Response:

1. Monitor for directory traversal patterns: Look for ../ sequences in HTTP request parameters.

2. Check for unexpected file inclusions: Monitor server logs for attempts to include files outside the web root.

3. Implement Web Application Firewall (WAF) rules: Block requests containing ../ or /etc/passwd patterns.

4. Audit code: Review all include() and require() statements for proper input validation.

5. Apply virtual patching: If a patch is not available, use a WAF to block the vulnerable parameter.

Indicators of Compromise (IOCs)

• HTTP Request Patterns:

  • GET /wp-content/themes/diza/*.php?file=../../../../wp-config
  • GET /wp-content/themes/diza/*.php?file=../../../../etc/passwd
  • GET /wp-content/themes/diza/*.php?file=php://filter/convert.base64-encode/resource=wp-config

• Log Entries:

  • "GET /wp-content/themes/diza/vulnerable-page.php?file=../../../../wp-config HTTP/1.1" 200
  • "GET /wp-content/themes/diza/vulnerable-page.php?file=php://filter/... HTTP/1.1" 200

• File System Artifacts:

  • Unexpected files in the web root (e.g., shell.php, cmd.php)
  • Modified .htaccess files

Detection Engineering

YARA Rule

rule Detect_Diza_LFI_Exploit {
    meta:
        description = "Detects attempts to exploit CVE-2025-68544 in Diza theme"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-68544"
    strings:
        $traversal = /\.\.\/\.\.\/\.\.\/\.\.\/(wp-config|etc\/passwd|proc\/self\/environ)/
        $param = /file=/
    condition:
        $param and $traversal
}

Sigma Rule

title: Diza Theme LFI Exploitation Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects HTTP requests attempting to exploit CVE-2025-68544
author: Valters IT
date: 2025-01-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 
            - 'file=../../../../wp-config'
            - 'file=../../../../etc/passwd'
            - 'file=php://filter/'
    condition: selection
falsepositives:
    - Legitimate use of directory traversal in other contexts (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-68544 Diza Theme LFI Attempt";
    flow:to_server,established;
    content:"GET"; http_method;
    content:"/wp-content/themes/diza/"; http_uri;
    content:"file="; http_uri;
    pcre:"/\.\.\/\.\.\/\.\.\/\.\.\/(wp-config|etc\/passwd|proc\/self\/environ)/Ui";
    sid:1000001;
    rev:1;
    reference:cve,2025-68544;
    classtype:attempted-recon;
)

Remediation & Mitigation

1. Immediate Action: Disable or remove the Diza theme until a patch is available. Switch to a different theme.

2. Virtual Patching: Use a WAF to block requests containing ../ or php:// in the vulnerable parameter.

3. Code Fix: Implement a whitelist of allowed files for inclusion, or use realpath() to resolve the path and ensure it is within the allowed directory.

   $base_dir = '/var/www/html/wp-content/themes/diza/includes/';
   $file = realpath($base_dir . $_GET['file'] . '.php');
   if (strpos($file, $base_dir) === 0) {
       include($file);
   } else {
       // Deny access
   }
   

4. Monitor: Continuously monitor logs for exploitation attempts.

5. Update: Watch for official patches from Thembay and apply them immediately.

Report generated by Valters IT DevSecOps & CTI Division