CVE-2024-43136

Executive Summary

CVE-2024-43136 is a Missing Authorization vulnerability in the Sunshine Photo Cart WordPress plugin (versions <= 3.2.1). This flaw allows an unauthenticated attacker to bypass authorization checks and perform unauthorized actions, potentially leading to data exposure or limited manipulation of photo cart data. The vulnerability is classified as CWE-862 (Missing Authorization) and carries a CVSS v3.1 base score of 4.3 (Medium). As of this report, no official patch has been released, and no public proof-of-concept (PoC) or exploit code is available. The EPSS score is 0.0%, indicating a very low probability of active exploitation in the wild.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users are advised to monitor the plugin's page for updates and consider disabling the plugin if no patch is available.

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) – Impact confined to the vulnerable component.
• Confidentiality (C): None (N) – No data disclosure.
• Integrity (I): Low (L) – Limited modification possible.
• Availability (A): None (N) – No denial of service.

Threat Level: Medium. The vulnerability is easy to exploit but has limited impact.

Deep Dive & Mechanics

The vulnerability resides in the Sunshine Photo Cart plugin's authorization logic. The plugin fails to properly validate user permissions when processing certain AJAX actions or REST API endpoints. Specifically, the sunshine_photo_cart plugin uses wp_ajax_* and wp_ajax_nopriv_* hooks without checking for the required capabilities (e.g., edit_posts, manage_options). This allows any unauthenticated visitor to trigger actions intended only for authenticated users.

The missing authorization check likely occurs in functions handling cart operations, such as adding/removing items, updating quantities, or viewing order data. An attacker can craft HTTP requests to these endpoints and bypass the intended access controls.

Vulnerable vs. Patched Code

Since no patch is available, we can only describe the vulnerable pattern.

Vulnerable Code (Hypothetical):

add_action('wp_ajax_nopriv_sunshine_add_to_cart', 'sunshine_add_to_cart_handler');
function sunshine_add_to_cart_handler() {
    // No capability check
    $product_id = $_POST['product_id'];
    // Process cart addition...
}

Patched Code (Expected):

add_action('wp_ajax_nopriv_sunshine_add_to_cart', 'sunshine_add_to_cart_handler');
function sunshine_add_to_cart_handler() {
    if (!current_user_can('edit_posts')) {
        wp_die('Unauthorized', 403);
    }
    $product_id = $_POST['product_id'];
    // Process cart addition...
}

Exploitation & Lab Setup

Red Team (Attack Simulation)

1. Setup: Install WordPress with Sunshine Photo Cart <= 3.2.1 on a local or cloud instance.
2. Recon: Identify AJAX endpoints by analyzing the plugin's JavaScript files or using a proxy (e.g., Burp Suite).
3. Exploit: Send a crafted POST request to the vulnerable endpoint without authentication.

Example Request:

POST /wp-admin/admin-ajax.php HTTP/1.1
Host: target-site.com
Content-Type: application/x-www-form-urlencoded

action=sunshine_add_to_cart&product_id=123&quantity=10

4. Verify: Check if the cart is updated without being logged in.

Blue Team (Defense & Detection)

• Monitor: Log all requests to admin-ajax.php and flag those with action parameters starting with sunshine_ from unauthenticated users.
• Harden: Implement a Web Application Firewall (WAF) rule to block requests to admin-ajax.php with action=sunshine_* unless the user is authenticated.
• Audit: Review plugin code for missing current_user_can() checks.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /wp-admin/admin-ajax.php with action=sunshine_* parameters from unauthenticated IPs.
• Logs: WordPress debug logs showing wp_ajax_nopriv_sunshine_* actions triggered without a valid nonce or user session.
• File: Modified cart data in the wp_options table (e.g., sunshine_cart_* entries) without corresponding user login.

Detection Engineering

YARA Rule

rule Detect_Sunshine_Photo_Cart_Missing_Auth {
    meta:
        description = "Detects exploitation attempts of CVE-2024-43136"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-43136"
    strings:
        $ajax_action = /action=sunshine_[a-z_]+/
        $nopriv = "wp_ajax_nopriv_sunshine"
    condition:
        $ajax_action and $nopriv
}

Sigma Rule

title: CVE-2024-43136 - Sunshine Photo Cart Missing Authorization
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated requests to Sunshine Photo Cart AJAX endpoints
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains: 'action=sunshine_'
    condition: selection
falsepositives:
    - Legitimate plugin usage (rare)
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2024-43136 - Sunshine Photo Cart Missing Authorization Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"admin-ajax.php"; http_uri;
    content:"action=sunshine_"; http_client_body;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

1. Immediate: Disable the Sunshine Photo Cart plugin until a patch is released.
2. Short-term: Implement a WAF rule to block unauthenticated requests to admin-ajax.php with action=sunshine_*.
3. Long-term: Contact the plugin vendor for a fix or consider replacing the plugin with an alternative.
4. Monitor: Review access logs for suspicious patterns and enable WordPress audit logging.

Valters IT
Securing Digital Frontiers