CVE-2025-68984

Executive Summary

CVE-2025-68984 is a critical PHP Local File Inclusion (LFI) vulnerability affecting the Puca WordPress theme by Thembay, up to version 2.6.39. The vulnerability stems from improper control of filenames used in PHP include/require statements, 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 source code. The CVSS score is 7.5 (High), with a network attack vector and no authentication required. No public exploit code or patch is currently available, making this a high-priority zero-day risk for WordPress sites using the affected theme.

Supply Chain & Package Security

This vulnerability is specific to the WordPress ecosystem, specifically the Puca theme by Thembay. As a WordPress theme, it is distributed via the official WordPress theme repository or directly by Thembay. Users should verify their theme version and monitor for updates. No NPM, PyPI, Go, or Ruby packages are involved.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
• Base Score: 7.5 (High)
• Attack Vector: Network (AV:N) – Exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – Vulnerability affects only the vulnerable component.
• Confidentiality Impact: High (C:H) – Full file read capability.
• Integrity Impact: None (I:N) – No file modification.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: High. The low complexity and lack of authentication make this easily exploitable by attackers to read sensitive server files.

Deep Dive & Mechanics

The vulnerability is a PHP Local File Inclusion (LFI) in the Puca WordPress theme. The theme likely uses a dynamic include or require statement where the filename is constructed from user-supplied input (e.g., via $_GET, $_POST, or $_COOKIE parameters) without proper sanitization or validation. For example, a vulnerable code snippet might look like:

<?php
$page = $_GET['page'];
include("pages/" . $page . ".php");
?>

An attacker can manipulate the page parameter to include arbitrary files by using path traversal sequences (e.g., ../../../../etc/passwd%00). The null byte (%00) or other techniques may be used to bypass file extension appending. Since the vulnerability is in a WordPress theme, it is triggered when the theme processes certain HTTP requests, typically via a shortcode, template tag, or custom page handler.

Key Points:

• The vulnerability is classified as CWE-98: Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion'), but in this case, it is limited to local file inclusion (LFI) as per the description.
• No authentication is required, making it accessible to any unauthenticated visitor.
• The impact is limited to reading files on the server; remote code execution (RCE) is not directly possible unless combined with file upload or other vulnerabilities.

Vulnerable vs. Patched Code

Since no patch is available, we can only hypothesize the vulnerable pattern and the expected fix.

Vulnerable Code (Hypothetical):

<?php
// In a theme template file (e.g., page.php)
$template = $_GET['template'];
include( get_template_directory() . '/templates/' . $template . '.php' );
?>

Patched Code (Expected):

<?php
// Whitelist allowed templates
$allowed_templates = array('default', 'full-width', 'sidebar');
$template = $_GET['template'];
if ( in_array( $template, $allowed_templates ) ) {
    include( get_template_directory() . '/templates/' . $template . '.php' );
} else {
    // Fallback to default
    include( get_template_directory() . '/templates/default.php' );
}
?>

The patch would involve:

1. Input validation: Use a whitelist of allowed values.
2. Path sanitization: Remove path traversal characters (e.g., ../).
3. Use of basename(): Extract only the filename to prevent directory traversal.
4. Avoid dynamic includes: Use static file mapping or switch statements.

Exploitation & Lab Setup

Red Team (Attacker)

Prerequisites:

• A WordPress site running Puca theme version <= 2.6.39.
• Knowledge of the vulnerable parameter (e.g., page, template, file).

Exploitation Steps:

1. Identify the vulnerable endpoint: Use a web fuzzer (e.g., Burp Suite, ffuf) to find parameters that cause file inclusion errors.
2. Craft the payload: Use path traversal to read sensitive files.
   • Example: http://target.com/?page=../../../../etc/passwd%00
   • Example: http://target.com/?template=../../../wp-config.php
3. Execute: Send the request and observe the response for file contents.

Lab Setup:

• Install a local WordPress instance with Puca theme version 2.6.39.
• Use a tool like curl to test:

  curl -v "http://localhost/wp-content/themes/puca/?page=../../../../etc/passwd"
  

Expected Output:

• The contents of /etc/passwd or other files will be displayed in the HTTP response.

Blue Team (Defender)

Detection:

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

Hunting:

• Search for requests containing ../../ in the query string.
• Check for error messages like "Warning: include(): Failed opening" in logs.

Mitigation:

• Immediately update the theme if a patch becomes available.
• If no patch, disable the theme or apply a virtual patch via WAF.
• Restrict file permissions on sensitive files (e.g., wp-config.php should not be readable by the web server user).

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests containing ../ or %2e%2e%2f in query parameters.
  • Requests to /wp-content/themes/puca/ with unusual parameters.
  • Responses containing file contents like root:x:0:0:root:/root:/bin/bash or DB_NAME.

• File IOCs:

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

• Behavioral IOCs:

  • Repeated requests to the same endpoint with varying path traversal payloads.
  • User-agent strings from automated tools (e.g., curl, python-requests).

Detection Engineering

YARA Rule

rule CVE_2025_68984_LFI_Puca {
    meta:
        description = "Detects path traversal attempts targeting Puca theme LFI"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-68984"
    strings:
        $path_traversal = /(\.\.\/|\.\.\\|%2e%2e%2f|%2e%2e%5c)/ nocase
        $puca_theme = "/wp-content/themes/puca/" nocase
    condition:
        $puca_theme and #path_traversal > 0
}

Sigma Rule

title: CVE-2025-68984 Puca Theme LFI Attempt
id: 8a4b3c2d-1e5f-6a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects path traversal attempts in HTTP requests to Puca theme
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-68984
logsource:
    category: webserver
    product: apache
    service: access_log
detection:
    selection:
        cs-uri-query|contains:
            - '../'
            - '..\\'
            - '%2e%2e%2f'
            - '%2e%2e%5c'
        cs-uri-stem|contains: '/wp-content/themes/puca/'
    condition: selection
falsepositives:
    - Legitimate use of path traversal in other contexts (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-68984 Puca Theme LFI Attempt"; flow:to_server,established; content:"/wp-content/themes/puca/"; http_uri; content:"../"; http_uri; distance:0; within:10; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Puca theme if possible and switch to a default WordPress theme (e.g., Twenty Twenty-Four).
2. Apply a virtual patch using a Web Application Firewall (WAF) to block path traversal patterns.
3. Monitor logs for exploitation attempts and block offending IPs.

Long-term Fix:

• Vendor patch: Await an official update from Thembay. Contact the vendor for a timeline.
• Manual fix: If you have access to the theme source code, apply the patched code pattern described above (whitelist allowed files, sanitize input).
• Upgrade: Once a patched version is released (e.g., > 2.6.39), update immediately.

Workarounds:

• Use a security plugin like Wordfence to add LFI protection rules.
• Restrict file permissions on sensitive files (e.g., chmod 600 wp-config.php).
• Disable PHP allow_url_include in php.ini (though this is for RFI, not LFI).

Valters IT
Securing Digital Frontiers