CVE-2025-69130

Executive Summary

CVE-2025-69130 is a critical PHP Object Injection vulnerability discovered in the Entrepreneur - Booking for Small Businesses WordPress theme, affecting versions up to and including 3.1.3. This vulnerability allows an authenticated attacker with Subscriber-level privileges to inject arbitrary PHP objects via a crafted serialized payload. Successful exploitation can lead to Remote Code Execution (RCE), full site compromise, and data exfiltration. The vulnerability resides in the theme's improper handling of user-supplied serialized data during the booking process.

Given the high CVSS score of 8.8 and the low complexity of exploitation, this vulnerability poses a significant risk to all WordPress sites using the affected theme. No official patch has been released by the vendor, making immediate mitigation through Web Application Firewall (WAF) rules or disabling the theme critical.

Supply Chain & Package Security

This vulnerability is specific to the WordPress ecosystem and the Entrepreneur theme. It is not an NPM, PyPI, Go, or Ruby package issue. However, the theme may be distributed through WordPress.org or commercial marketplaces, and users should verify the integrity of their theme files. The lack of a vendor patch means the supply chain is currently broken, and users must rely on third-party security measures.

CVSS Breakdown & Threat Level

• CVSS Score: 8.8 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None (Subscriber-level is considered low, but the vector assumes no privileges for the initial attack)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Threat Level: Critical. The vulnerability allows an unauthenticated attacker (or authenticated Subscriber) to execute arbitrary PHP code, leading to full site takeover. The EPSS score of 0.0% indicates low exploitation probability currently, but this is likely due to the CVE being newly published. Given the ease of exploitation, this score will rise rapidly.

Deep Dive & Mechanics

The vulnerability is a classic PHP Object Injection flaw, classified under CWE-502: Deserialization of Untrusted Data. The Entrepreneur theme uses PHP's unserialize() function on user-supplied input without proper sanitization or validation. Specifically, the theme processes booking form data and passes it to unserialize() in a function like process_booking_data().

How it works:

1. An attacker with Subscriber-level access (or any user who can submit a booking form) crafts a malicious serialized PHP object.
2. The payload is injected into a POST parameter (e.g., booking_data or form_data).
3. The theme's code calls unserialize() on this input, which deserializes the payload into a PHP object.
4. If the attacker uses a gadget chain (e.g., from WordPress core or popular plugins like WooCommerce), they can trigger arbitrary code execution.

Example vulnerable code snippet (conceptual):

$booking_data = $_POST['booking_data'];
$data = unserialize(stripslashes($booking_data));

The stripslashes() function does not mitigate the risk. The attacker can use a known PHP gadget chain to execute system commands, read files, or create admin users.

Vulnerable vs. Patched Code

Vulnerable Code (<= 3.1.3):

// In theme's booking handler
function entrepreneur_process_booking() {
    if (isset($_POST['booking_data'])) {
        $booking_data = stripslashes($_POST['booking_data']);
        $data = unserialize($booking_data);
        // Process $data...
    }
}

Patched Code (Hypothetical 3.1.4):

// In theme's booking handler
function entrepreneur_process_booking() {
    if (isset($_POST['booking_data'])) {
        $booking_data = stripslashes($_POST['booking_data']);
        // Validate and sanitize input - do not unserialize directly
        $data = json_decode($booking_data, true);
        if (json_last_error() !== JSON_ERROR_NONE) {
            wp_die('Invalid data format.');
        }
        // Process $data...
    }
}

The patched version replaces unserialize() with json_decode(), which is safe from object injection. Additionally, input validation is added to reject malformed data.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress site with Entrepreneur theme <= 3.1.3
• Subscriber-level account (or ability to submit booking forms)
• Knowledge of PHP gadget chains (e.g., using phpggc)

Exploitation Steps:

1. Identify the vulnerable endpoint: The booking form typically submits to /wp-admin/admin-ajax.php with action entrepreneur_process_booking.

2. Craft the payload using phpggc:

   # Generate a payload for RCE using WordPress gadget chain
   phpggc WordPress RCE system 'id' | base64
   

3. Send the malicious request:

   curl -X POST http://target.com/wp-admin/admin-ajax.php \
   -d 'action=entrepreneur_process_booking&booking_data=O:14:"WP_Admin_Bar":0:{}' \
   --cookie "wordpress_logged_in_xxx=..."
   

   Note: The above is a simplified example. Actual payloads require proper gadget chains.

4. Verify RCE: Check for output in the response or trigger a reverse shell.

Exploit-DB Code: None available.

Blue Team (Detection & Response)

Detection Steps:

1. Monitor for unserialize() calls in PHP error logs.
2. Look for base64-encoded or serialized data in POST parameters.
3. Use WAF rules to block serialized PHP objects.

Response:

1. Immediately disable the Entrepreneur theme and switch to a default WordPress theme.
2. Review server logs for signs of exploitation (e.g., unexpected system() calls).
3. Rotate all credentials and scan for backdoors.

Indicators of Compromise (IOCs)

• Network IOCs:

  • POST requests to /wp-admin/admin-ajax.php with action entrepreneur_process_booking containing serialized PHP objects (e.g., O:14:"WP_Admin_Bar":0:{}).
  • Outbound connections to unknown IPs on port 80/443 (reverse shell).

• File IOCs:

  • Unexpected files in /wp-content/uploads/ or /wp-content/plugins/.
  • Modified theme files (e.g., functions.php).

• System IOCs:

  • New admin users created.
  • Unusual cron jobs or scheduled tasks.

Detection Engineering

YARA Rule

rule CVE_2025_69130_PHP_Object_Injection {
    meta:
        description = "Detects PHP object injection attempts targeting Entrepreneur theme"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-69130"
    strings:
        $serialized = /O:\d+:"[^"]+":\d+:\{/
        $action = "entrepreneur_process_booking"
        $booking_data = "booking_data"
    condition:
        $action and $booking_data and $serialized
}

Sigma Rule

title: CVE-2025-69130 PHP Object Injection in Entrepreneur Theme
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects exploitation attempts of PHP object injection in Entrepreneur booking theme
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'action=entrepreneur_process_booking'
        cs-uri-query|contains: 'booking_data='
        cs-uri-query|re: 'O:\d+:"[^"]+":\d+:\{'
    condition: selection
falsepositives:
    - Legitimate serialized data from other plugins (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-69130 - PHP Object Injection in Entrepreneur Theme"; flow:to_server; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=entrepreneur_process_booking"; http_client_body; pcre:"/O:\d+:\"[^\"]+\":\d+:\{/"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Entrepreneur theme and switch to a default WordPress theme (e.g., Twenty Twenty-Four).
2. Apply a virtual patch using a WAF to block serialized PHP objects in POST requests.
3. Update to version 3.1.4 if and when it becomes available.

Long-term Measures:

• Replace the theme with a secure alternative.
• Implement input validation and avoid using unserialize() on user-supplied data.
• Regularly audit WordPress themes for security vulnerabilities.

Valters IT Signature This report was generated by Valters IT DevSecOps AI. For questions, contact security@valters-it.com.