CVE-2025-68546

Executive Summary

CVE-2025-68546 is a critical PHP Local File Inclusion (LFI) vulnerability discovered in the Nika WordPress theme developed by Thembay. The flaw resides in an improper control of filename for 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 vulnerability affects all versions of Nika up to and including 1.2.14. No patch is currently available, and no public proof-of-concept (PoC) has been released. The CVSS score of 7.5 reflects the high confidentiality impact and ease of exploitation over the network without authentication.

Supply Chain & Package Security

This vulnerability is specific to the WordPress ecosystem as a theme component. Users who have installed the Nika theme from Thembay are at risk. Since no patch exists, the supply chain risk is elevated, and users must consider removing or replacing the theme until a fix is provided.

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 remains 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 expose sensitive server data.

Deep Dive & Mechanics

The vulnerability is a classic PHP Local File Inclusion (CWE-98) in the Nika WordPress theme. The theme likely uses a dynamic include statement such as include($_GET['page']); or similar, without proper sanitization or whitelisting. An attacker can manipulate the page parameter (or similar) to traverse directories and include arbitrary files.

For example, a request like:

http://target.com/wp-content/themes/nika/index.php?page=../../../../etc/passwd

could cause the server to include /etc/passwd, exposing user account information. The vulnerability is classified as "PHP Remote File Inclusion" in the description, but the impact is local file inclusion, as remote inclusion would require allow_url_include to be enabled, which is rare.

The attack does not require authentication, making it accessible to any remote attacker. The lack of a patch means all installations are vulnerable until the theme is updated or removed.

Vulnerable vs. Patched Code

Since no patch is available, we can only hypothesize the vulnerable code pattern. A typical vulnerable snippet might look like:

// Vulnerable code in Nika theme (hypothetical)
$page = $_GET['page'];
include($page . '.php');

A patched version would implement strict whitelisting or path validation:

// Patched code (hypothetical)
$allowed_pages = array('home', 'about', 'contact');
$page = $_GET['page'];
if (in_array($page, $allowed_pages)) {
    include($page . '.php');
} else {
    // Default page
    include('home.php');
}

Without an official patch, users must rely on workarounds such as Web Application Firewall (WAF) rules or disabling the theme.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress instance with the Nika theme (<=1.2.14) installed and activated.
• No authentication required.

Exploitation Steps:

1. Identify the vulnerable parameter. Common parameters in themes include page, template, file, or include. Use a wordlist or fuzzing tool.

2. Craft a request to include a sensitive file:

curl "http://target.com/wp-content/themes/nika/index.php?page=../../../../etc/passwd"

3. If successful, the response will contain the contents of /etc/passwd.

Example Output:

root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
...

Advanced Exploitation:

• Use PHP wrappers to read source code: php://filter/convert.base64-encode/resource=index.php
• Attempt to include log files for RCE if file upload is possible.

Blue Team (Detection & Defense)

Detection:

• Monitor web server logs for directory traversal patterns (e.g., ../, ..\\, %2e%2e%2f).
• Look for requests to the Nika theme directory with suspicious parameters.

Defense:

• Immediately disable or remove the Nika theme if no patch is available.
• Implement a WAF rule to block directory traversal attempts.
• Restrict file inclusion to a whitelist of allowed paths.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests containing ../ or ..\\ in the query string targeting /wp-content/themes/nika/.
  • Requests with parameters like page, template, or file containing path traversal sequences.
  • Unusual file reads such as /etc/passwd, /etc/shadow, or wp-config.php in server logs.

• File System IOCs:

  • Unexpected inclusion of sensitive files in web server responses.
  • Presence of PHP error logs indicating failed include attempts.

• Log Entries:

  • Apache/Nginx access logs showing GET /wp-content/themes/nika/index.php?page=../../../../etc/passwd HTTP/1.1 with a 200 response.

Detection Engineering

YARA Rule

rule CVE_2025_68546_Nika_LFI {
    meta:
        description = "Detects attempts to exploit CVE-2025-68546 in Nika WordPress theme"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-68546"
    strings:
        $traversal1 = "../"
        $traversal2 = "..\\"
        $traversal3 = "%2e%2e%2f"
        $nika_path = "/wp-content/themes/nika/"
    condition:
        any of ($traversal*) and $nika_path
}

Sigma Rule

title: CVE-2025-68546 Nika WordPress Theme LFI Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects HTTP requests attempting to exploit Local File Inclusion in Nika theme
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - '../'
            - '..\\'
            - '%2e%2e%2f'
        cs-uri-stem|contains: '/wp-content/themes/nika/'
    condition: selection
falsepositives:
    - Legitimate use of path traversal in other contexts (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-68546 Nika WordPress Theme LFI Attempt"; flow:to_server,established; content:"/wp-content/themes/nika/"; http_uri; content:"../"; http_uri; distance:0; within:10; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Nika theme and switch to a default WordPress theme (e.g., Twenty Twenty-Four) until a patch is released.
2. Implement a Web Application Firewall (WAF) rule to block directory traversal patterns in requests to the theme directory.
3. Monitor logs for any signs of exploitation and rotate credentials if sensitive files were exposed.

Long-term Fix:

• Contact Thembay for an official patch. If none is forthcoming, consider replacing the theme with a secure alternative.
• Apply the principle of least privilege to the web server user to limit the impact of file inclusion.
• Regularly update all WordPress components and themes.

Valters IT Signature: This report was generated by Valters IT Cyber Threat Intelligence Division. For questions, contact threatintel@valtersit.com.