CVE-2025-68536

Executive Summary

CVE-2025-68536 is a critical PHP Local File Inclusion (LFI) vulnerability affecting the Zota WordPress plugin by Thembay, up to and including version 1.3.14. 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, including configuration files, source code, and potentially credentials. The CVSS score of 8.1 (High) reflects the ease of exploitation (no authentication required) and the high impact on confidentiality. As a WordPress plugin vulnerability, it is part of the broader WordPress ecosystem and does not implicate the underlying web server (Apache/Nginx).

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository and third-party marketplaces. Users who installed the plugin from any source are at risk. Since the patch status is unknown, the supply chain risk is elevated; users should consider the plugin compromised and remove it until a patch is confirmed.

CVSS Breakdown & Threat Level

• CVSS Score: 8.1 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: None
• Availability Impact: None

The threat level is High due to the trivial exploitation path and the potential for significant data leakage. The EPSS score of 0.0% suggests low current exploitation activity, but this may change as proof-of-concept code emerges.

Deep Dive & Mechanics

The vulnerability exists in the Zota plugin's handling of file inclusion. The plugin likely uses a user-supplied parameter (e.g., page, file, template) 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:

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

By using path traversal sequences (e.g., ../../../etc/passwd), an attacker can include sensitive files. The .php extension appended by the code can be bypassed using a null byte injection (in older PHP versions) or by using a wrapper like php://filter to read non-PHP files.

Attack flow:

1. Attacker identifies a parameter in the Zota plugin that controls file inclusion.
2. Attacker crafts a request with a path traversal payload, e.g., ?file=../../../etc/passwd%00.
3. The server includes the target file, exposing its contents in the response.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable pattern. A patched version would implement strict input validation, whitelisting allowed files, and using realpath() to resolve paths.

Vulnerable code (conceptual):

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

Patched code (conceptual):

$allowed_files = ['home', 'about', 'contact'];
$file = $_GET['file'];
if (in_array($file, $allowed_files)) {
    include("templates/" . $file . ".php");
} else {
    // Handle error
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress instance with Zota plugin <= 1.3.14 installed and activated.
• Knowledge of the vulnerable parameter (e.g., page, file).

Exploitation steps:

1. Enumerate the vulnerable parameter by fuzzing common parameters like page, file, template, include.
2. Test for LFI using path traversal:

   GET /wp-content/plugins/zota/vulnerable.php?file=../../../etc/passwd HTTP/1.1
   Host: target.com
   

3. If the response contains the contents of /etc/passwd, the vulnerability is confirmed.
4. Use PHP wrappers to read PHP source code:

   GET /wp-content/plugins/zota/vulnerable.php?file=php://filter/convert.base64-encode/resource=index.php HTTP/1.1
   

Example curl command:

curl -v "http://target.com/wp-content/plugins/zota/vulnerable.php?file=../../../etc/passwd"

Blue Team (Detection & Hardening)

Detection:

• Monitor web server logs for path traversal patterns (e.g., ../, %2e%2e%2f).
• Look for requests to Zota plugin files with suspicious parameters.
• Use WAF rules to block path traversal attempts.

Hardening:

• Disable the Zota plugin immediately if not essential.
• Apply virtual patching via WAF to block LFI patterns.
• Ensure PHP allow_url_include is disabled.
• Use open_basedir to restrict file access.

Indicators of Compromise (IOCs)

• File paths accessed: /etc/passwd, /etc/shadow, /wp-config.php, /proc/self/environ
• URL patterns: ?file=, ?page=, ?template= followed by ../ or php://
• Log entries: Requests containing %00, %2e%2e%2f, or php://filter
• Response anomalies: Unexpected inclusion of system files in HTTP responses

Detection Engineering

YARA Rule

rule CVE_2025_68536_LFI_Detection {
    meta:
        description = "Detects LFI attempts targeting CVE-2025-68536 in Zota plugin"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "CVE-2025-68536"
    strings:
        $path_traversal = /(\.\.\/|\.\.\\|%2e%2e%2f|%2e%2e%5c)/
        $php_wrapper = /php:\/\/(filter|input|stdin)/
        $zota_param = /(file|page|template|include)=/
    condition:
        $zota_param and ($path_traversal or $php_wrapper)
}

Sigma Rule

title: CVE-2025-68536 Zota Plugin LFI Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects path traversal attempts targeting the Zota WordPress plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-uri-query|contains:
            - 'file=../'
            - 'page=../'
            - 'template=../'
            - 'include=../'
            - 'php://filter'
            - 'php://input'
    condition: selection
falsepositives:
    - Legitimate use of similar parameters in other plugins
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-68536 Zota Plugin LFI Attempt"; flow:to_server,established; content:"/wp-content/plugins/zota/"; http_uri; content:"file="; http_uri; pcre:"/(\.\.\/|%2e%2e%2f|php:\/\/)/Ri"; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate actions:

1. Disable the Zota plugin until a patch is released.
2. Implement WAF rules to block path traversal and PHP wrapper usage.
3. Review server logs for signs of exploitation.

Long-term fixes:

• Monitor the vendor's website for a patched version.
• Consider replacing the plugin with an alternative.
• Apply the principle of least privilege to the web server user.
• Regularly update all WordPress components.

Valters IT signature: This report was generated by Valters IT Cyber Threat Intelligence Division. For questions, contact cti@valters-it.com.