CVE-2025-23948

Executive Summary

CVE-2025-23948 is a critical PHP Local File Inclusion (LFI) vulnerability discovered in the WordPress plugin Background animation blocks (background-animation-blocks) by Webarea, affecting versions through 2.1.5. 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, WordPress configuration files (wp-config.php), or other system files. The CVSS score of 8.1 (High) reflects the ease of exploitation (no authentication required) and the high confidentiality impact. No public proof-of-concept (PoC) or patch is currently available, making this a zero-day threat for unpatched installations.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users who installed the plugin from the WordPress dashboard or via direct download are at risk. The plugin is not available on NPM, PyPI, Go, or Ruby ecosystems. The lack of a patch from the vendor (Webarea) means that all installations of the plugin version 2.1.5 and below are vulnerable. Organizations should treat this as a high-priority supply chain risk and consider removing the plugin until a fix is released.

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 and the impacted component are 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 lead to complete disclosure of sensitive server-side files.

Deep Dive & Mechanics

The vulnerability exists in the background-animation-blocks plugin's PHP code, likely in a function that dynamically includes files based on user-supplied input (e.g., a page or file parameter). The plugin fails to sanitize or validate the filename before passing it to PHP functions like include(), require(), or include_once(). An attacker can manipulate the input to traverse directories using ../ sequences and include arbitrary files from the server.

Example vulnerable code pattern:

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

This allows an attacker to request ?file=../../../../etc/passwd to read the password file (though the .php extension may need to be bypassed using null byte injection or path truncation in older PHP versions, or by using wrappers like php://filter).

WordPress-specific context: The plugin is a WordPress plugin, meaning it runs within the WordPress environment. The vulnerability is not related to Apache or Nginx configuration; it is purely a PHP code flaw in the plugin.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable code pattern and what a fix would look like.

Vulnerable code (hypothetical):

<?php
// background-animation-blocks/includes/loader.php
$template = $_GET['template'];
include( plugin_dir_path( __FILE__ ) . 'templates/' . $template . '.php' );
?>

Patched code (recommended):

<?php
// background-animation-blocks/includes/loader.php
$allowed_templates = array('default', 'slider', 'parallax');
$template = isset($_GET['template']) ? $_GET['template'] : 'default';
if (in_array($template, $allowed_templates, true)) {
    include( plugin_dir_path( __FILE__ ) . 'templates/' . $template . '.php' );
} else {
    // Handle error or load default
    include( plugin_dir_path( __FILE__ ) . 'templates/default.php' );
}
?>

The fix involves whitelisting allowed filenames and rejecting any input that does not match.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install WordPress on a local server (e.g., using XAMPP or Docker).
2. Install the vulnerable plugin background-animation-blocks version 2.1.5.
3. Identify the vulnerable parameter (likely file, template, or page) by reviewing the plugin source code.

Exploitation Steps:

1. Use a web browser or tool like curl to send a crafted request:

   curl "http://target/wp-content/plugins/background-animation-blocks/includes/loader.php?file=../../../../../../etc/passwd"
   

2. If the plugin uses a wrapper, try:

   curl "http://target/wp-content/plugins/background-animation-blocks/includes/loader.php?file=php://filter/convert.base64-encode/resource=../../../../../../etc/passwd"
   

3. Read sensitive WordPress files:

   curl "http://target/wp-content/plugins/background-animation-blocks/includes/loader.php?file=../../../../../../wp-config.php"
   

Note: No public exploit code is available, but the technique is standard LFI.

Blue Team (Defensive)

Detection:

• Monitor web server logs for requests containing ../, php://, or file= parameters targeting the plugin directory.
• Look for unusual file paths in HTTP requests (e.g., /etc/passwd, /wp-config.php).

Hunting:

• Search for requests to /wp-content/plugins/background-animation-blocks/ with suspicious query strings.
• Use the Sigma rule provided in Detection Engineering.

Mitigation:

• Immediately disable or remove the plugin until a patch is released.
• Implement a Web Application Firewall (WAF) rule to block LFI patterns.
• Restrict file inclusion via PHP configuration (disable allow_url_include and allow_url_fopen).

Indicators of Compromise (IOCs)

• File paths accessed: /etc/passwd, /etc/shadow, /wp-config.php, /proc/self/environ
• URL patterns: ?file=, ?template=, ?page= with path traversal sequences
• Log entries: HTTP 200 responses to requests containing ../ in the query string targeting the plugin directory
• Network traffic: Outbound connections from the server if remote file inclusion is attempted (though this is LFI, not RFI)

Detection Engineering

YARA Rule

rule CVE_2025_23948_LFI_Detection {
    meta:
        description = "Detects attempts to exploit CVE-2025-23948 LFI in Background animation blocks plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-23948"
    strings:
        $s1 = "background-animation-blocks" nocase
        $s2 = "../" ascii
        $s3 = "file=" ascii
        $s4 = "php://" ascii
        $s5 = "/etc/passwd" ascii
    condition:
        all of ($s1, $s2) and any of ($s3, $s4, $s5)
}

Sigma Rule

title: CVE-2025-23948 LFI Exploitation Attempt
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects HTTP requests targeting the Background animation blocks plugin with path traversal or file inclusion patterns.
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-uri-query|contains:
            - 'background-animation-blocks'
            - '../'
            - 'php://'
            - 'file='
    condition: selection
falsepositives:
    - Legitimate use of the plugin with similar parameters (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-23948 LFI Attempt - Background animation blocks"; flow:to_server,established; content:"background-animation-blocks"; http_uri; content:"../"; http_uri; content:"file="; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin – Deactivate and delete the background-animation-blocks plugin from all WordPress installations.
2. Apply virtual patching – Use a WAF to block requests containing ../ or php:// in the query string for the plugin directory.
3. Monitor logs – Review web server logs for any signs of exploitation.

Long-term Fix:

• The vendor (Webarea) must release a patched version that implements input validation and whitelisting. Until then, do not use the plugin.
• Consider replacing the plugin with an alternative that provides similar functionality but is actively maintained.

General Hardening:

• Ensure PHP allow_url_include is disabled.
• Keep all WordPress plugins and themes updated.
• Use a security plugin like Wordfence to detect and block LFI attempts.

Valters IT
Securing Digital Frontiers