CVE-2025-68537

Executive Summary

CVE-2025-68537 is a critical PHP Local File Inclusion (LFI) vulnerability discovered in the Zota WordPress plugin by Thembay, affecting versions up to and including 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, such as reading /etc/passwd, configuration files, or WordPress wp-config.php. The CVSS score of 7.5 (High) reflects the ease of exploitation (no authentication required) and the high impact on confidentiality. 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 the WordPress plugin ecosystem. The Zota plugin is distributed via the official WordPress plugin repository and third-party marketplaces. Users who installed the plugin from any source are at risk. The lack of a patch from the vendor (Thembay) means that supply chain security is compromised, and users must rely on manual mitigation or removal of the plugin.

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 remains the same.
• Confidentiality (C): High (H) – Full file read access.
• 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 files, including database credentials.

Deep Dive & Mechanics

The Zota plugin likely uses a PHP construct similar to include($_GET['file']); or require($_GET['template']); without proper sanitization or path restriction. An attacker can manipulate the file parameter to traverse directories using ../ sequences and read arbitrary files. For example:

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

By sending ?file=../../../../etc/passwd%00, the attacker can null-terminate the string and bypass the .php extension, reading /etc/passwd. The vulnerability is classified as CWE-98: Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion'), though in this case it is limited to local file inclusion (LFI) due to allow_url_include being disabled by default.

Vulnerable vs. Patched Code

Vulnerable Code (Zota <= 1.3.14):

// Example of vulnerable include
$template = $_GET['template'];
include(plugin_dir_path(__FILE__) . 'templates/' . $template . '.php');

Patched Code (Hypothetical):

// Patched version with whitelist and path validation
$allowed_templates = ['default', 'custom', 'landing'];
$template = $_GET['template'];
if (in_array($template, $allowed_templates)) {
    include(plugin_dir_path(__FILE__) . 'templates/' . $template . '.php');
} else {
    // Error handling
}

The patched version uses a whitelist approach, ensuring only predefined template names can be included. Additionally, realpath() and path canonicalization should be used to prevent directory traversal.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install WordPress with Zota plugin version 1.3.14.
2. Ensure the plugin is active and accessible via http://target/wp-content/plugins/zota/.

Exploitation Steps:

1. Identify the vulnerable parameter (e.g., file, template, page).
2. Use a web browser or curl to test LFI:

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

3. If the response contains the contents of /etc/passwd, the vulnerability is confirmed.
4. For WordPress-specific data, read wp-config.php:

   curl "http://target/wp-content/plugins/zota/vulnerable.php?file=../../../../wp-config.php"
   

Note: No public exploit code is available; the above is a generic LFI technique.

Blue Team (Defensive)

Detection Steps:

1. Monitor web server logs for directory traversal patterns (e.g., ../, %2e%2e%2f).
2. Look for requests to Zota plugin files with suspicious parameters.
3. Check for outbound connections from the web server (though LFI is local, it may be used for further attacks).

Mitigation:

• Immediately disable or remove the Zota plugin until a patch is released.
• Implement a Web Application Firewall (WAF) rule to block directory traversal attempts.
• Use file integrity monitoring to detect unauthorized file reads.

Indicators of Compromise (IOCs)

• File Paths: /etc/passwd, /etc/shadow, /wp-config.php, /proc/self/environ
• URL Patterns: ?file=, ?template=, ?page= followed by ../ sequences
• Log Entries: HTTP 200 responses to requests containing ../ in the query string
• Network: No specific network IOCs, as LFI is server-side

Detection Engineering

YARA Rule

rule CVE_2025_68537_Zota_LFI {
    meta:
        description = "Detects attempts to exploit CVE-2025-68537 in Zota WordPress plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-68537"
    strings:
        $s1 = "zota" nocase
        $s2 = "file=" nocase
        $s3 = "../" nocase
        $s4 = "wp-config.php" nocase
        $s5 = "/etc/passwd" nocase
    condition:
        all of ($s1, $s2) and 1 of ($s3, $s4, $s5)
}

Sigma Rule

title: CVE-2025-68537 Zota Plugin LFI Detection
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects directory traversal attempts targeting the Zota WordPress plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-uri-query|contains:
            - 'file=../'
            - 'template=../'
            - 'page=../'
        cs-uri-stem|contains: '/wp-content/plugins/zota/'
    condition: selection
falsepositives:
    - Legitimate use of relative paths (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-68537 Zota Plugin LFI Attempt"; flow:to_server,established; content:"/wp-content/plugins/zota/"; http_uri; content:"../"; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Disable or uninstall the Zota plugin until a patch is released.
2. Vendor Contact: Reach out to Thembay for an official patch or update.
3. WAF Rules: Deploy virtual patching via WAF to block ../ sequences in plugin parameters.
4. File Permissions: Ensure sensitive files (e.g., wp-config.php) have restrictive permissions (e.g., 640).
5. Monitoring: Enable detailed logging for all web requests and set up alerts for directory traversal patterns.
6. Alternative: If the plugin is critical, consider replacing it with a similar, actively maintained plugin.

Valters IT
Securing Digital Frontiers