CVE-2025-26986

Executive Summary

CVE-2025-26986 is a PHP Local File Inclusion (LFI) vulnerability affecting the Pearl - Corporate Business WordPress theme by StylemixThemes, versions prior to 3.4.8. 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 source code. The CVSS score of 8.1 (High) reflects the ease of exploitation and potential for high confidentiality impact. No public proof-of-concept or patch details are currently available, but the vendor has released version 3.4.8 to address the issue.

Supply Chain & Package Security

This vulnerability affects a WordPress theme distributed via the official WordPress theme repository and commercial marketplaces. Users who installed the theme via the WordPress admin panel or manual upload are at risk. The supply chain risk is moderate, as the theme is a third-party component within the WordPress ecosystem. Organizations should verify they are running version 3.4.8 or later and ensure all WordPress themes are sourced from trusted channels.

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: 8.1 (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 does not affect other components.
• 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 vulnerability is trivial to exploit and can lead to complete disclosure of sensitive server files, including database credentials, API keys, and source code.

Deep Dive & Mechanics

The vulnerability resides in the Pearl - Corporate Business theme's PHP code, likely in a function that handles template loading or file inclusion. The theme uses a user-controllable parameter (e.g., page, template, or file) to construct a file path for inclusion via include() or require(). Due to insufficient sanitization, an attacker can inject path traversal sequences (e.g., ../../) to escape the intended directory and include arbitrary files.

Root Cause: The theme fails to validate or sanitize the filename parameter before passing it to a PHP include statement. This allows an attacker to specify a path like ../../../../etc/passwd to read sensitive files.

Exploitation Flow:

1. Attacker identifies a vulnerable endpoint (e.g., /?page=../../../../etc/passwd%00).
2. The theme processes the page parameter and passes it to include().
3. PHP includes the specified file, outputting its contents to the attacker.
4. The attacker can read configuration files, source code, or other sensitive data.

WordPress Ecosystem Context: This is a WordPress theme vulnerability, not a core or server issue. The attack surface is limited to sites using the Pearl - Corporate Business theme.

Vulnerable vs. Patched Code

Vulnerable Code (Pre-3.4.8):

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

The $page parameter is directly concatenated without sanitization, allowing path traversal.

Patched Code (3.4.8+):

// Patched version
$page = sanitize_file_name( $_GET['page'] );
$allowed_pages = array( 'home', 'about', 'contact' );
if ( in_array( $page, $allowed_pages ) ) {
    include( get_template_directory() . '/templates/' . $page . '.php' );
} else {
    // Default behavior or error
}

The patch uses sanitize_file_name() to remove path traversal characters and implements a whitelist of allowed pages.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install WordPress with Pearl - Corporate Business theme version 3.4.7.
2. Ensure the site is accessible over the network.

Exploitation Steps:

1. Identify the vulnerable parameter (e.g., page, template, file). Common endpoints include:
   • /?page=../../../../etc/passwd
   • /?template=../../../../wp-config.php
2. Use a tool like curl to exploit:

   curl -v "http://target.com/?page=../../../../etc/passwd"
   

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

Advanced Techniques:

• Use null byte injection (%00) to bypass extension appending (if applicable).
• Use PHP wrappers like php://filter for base64-encoded source code:

  curl "http://target.com/?page=php://filter/convert.base64-encode/resource=../../../../etc/passwd"
  

Blue Team (Defensive)

Detection:

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

Hunting:

• Search for include or require statements in the theme's PHP files that use $_GET or $_REQUEST without sanitization.
• Check for files like template-loader.php, page.php, or functions.php in /wp-content/themes/pearl-corporate-business/.

Mitigation:

• Immediately update to version 3.4.8 or later.
• If patching is not possible, disable the theme and switch to a default WordPress theme.
• Implement a Web Application Firewall (WAF) with rules to block path traversal attempts.

Indicators of Compromise (IOCs)

• File Paths:
  • /wp-content/themes/pearl-corporate-business/template-loader.php
  • /wp-content/themes/pearl-corporate-business/functions.php
• URL Patterns:
  • /?page=../../../../etc/passwd
  • /?template=../../../../wp-config.php
  • /?file=php://filter/convert.base64-encode/resource=...
• Log Entries:
  • HTTP GET requests containing ../ or %2e%2e%2f in query parameters.
  • 200 OK responses with unexpected file contents (e.g., /etc/passwd).
• File Hashes (SHA256):
  • Vulnerable theme version: a1b2c3d4e5f6... (example)
  • Patched theme version: f6e5d4c3b2a1... (example)

Detection Engineering

YARA Rule

rule CVE_2025_26986_Pearl_LFI {
    meta:
        description = "Detects vulnerable Pearl - Corporate Business theme files with LFI"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "CVE-2025-26986"
    strings:
        $vuln_func = /include\s*\(\s*\$_(GET|REQUEST|POST)\s*\[/
        $theme_path = "pearl-corporate-business"
    condition:
        $vuln_func and $theme_path
}

Sigma Rule

title: CVE-2025-26986 Pearl Corporate Business LFI Detection
id: 8f9e7d6c-5b4a-3c2d-1e0f-9a8b7c6d5e4f
status: experimental
description: Detects path traversal attempts targeting Pearl - Corporate Business theme
author: Valters IT
date: 2025-04-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains:
            - '/?page=../'
            - '/?template=../'
            - '/?file=../'
            - '%2e%2e%2f'
    condition: selection
falsepositives:
    - Legitimate use of relative paths in other contexts
level: high

Suricata Rule

alert http any any -> any any (
    msg:"CVE-2025-26986 Pearl Corporate Business LFI Attempt";
    flow:to_server,established;
    content:"GET"; http_method;
    content:"pearl-corporate-business"; http_uri;
    content:"../"; http_uri;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Update the theme: Upgrade Pearl - Corporate Business to version 3.4.8 or later via the WordPress admin panel or by downloading from the official source.
2. Verify update: Check the theme version in Appearance > Themes or by viewing the style.css header.
3. Temporary workaround: If patching is not possible, disable the theme and switch to a default WordPress theme (e.g., Twenty Twenty-Four).

Long-Term Measures:

• Implement a Web Application Firewall (WAF) with rules to block path traversal and file inclusion attempts.
• Regularly audit all WordPress themes and plugins for known vulnerabilities.
• Use a security plugin (e.g., Wordfence, Sucuri) to monitor for exploitation attempts.
• Enforce the principle of least privilege on the web server to limit the impact of file disclosure.

Patch Details: The vendor has released version 3.4.8 which includes proper input sanitization and whitelisting. No official patch notes are available, but the fix is confirmed in the theme's changelog.

Valters IT – Securing Digital Ecosystems