CVE-2025-68535

Executive Summary

CVE-2025-68535 is a Missing Authorization vulnerability in the Sunshine Photo Cart WordPress plugin (versions <= 3.5.7.1). This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized data access or modification. 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 the vendor has not responded to disclosure attempts. The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the risk remains due to the lack of a patch.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed through the official WordPress plugin repository. Users who installed the plugin via the WordPress dashboard or manual upload are at risk. No known supply chain compromise has been reported, but the unpatched state increases the risk of future exploitation.

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) – Vulnerability does not affect other components.
• Confidentiality (C): None (N) – No direct data exposure.
• Integrity (I): Low (L) – Limited ability to modify data.
• Availability (A): None (N) – No impact on availability.

Threat Level: Medium. The vulnerability is easy to exploit but has limited impact. However, the lack of a patch elevates the risk for unmitigated installations.

Deep Dive & Mechanics

The vulnerability resides in the Sunshine Photo Cart plugin's access control logic. The plugin fails to properly validate user permissions when processing certain AJAX requests or REST API endpoints. Specifically, functions that should require administrative or editor-level privileges are accessible to unauthenticated users.

Root Cause: The plugin uses wp_ajax_nopriv_* hooks without proper capability checks, allowing any visitor to trigger actions intended for authenticated users. This is a classic case of Missing Authorization where the code assumes that if a user can reach the endpoint, they are authorized.

Attack Vector: An attacker can send crafted HTTP requests to the vulnerable endpoints, bypassing the intended access controls. For example, an endpoint designed to update plugin settings might be callable without authentication.

Impact: An attacker could:

• Modify plugin settings (e.g., pricing, gallery visibility).
• Access or delete customer data (if exposed via the same flawed logic).
• Potentially escalate privileges if combined with other vulnerabilities.

Vulnerable vs. Patched Code

Since no official patch exists, the following is a hypothetical fix based on common WordPress security practices.

Vulnerable Code (sunshine-photo-cart/includes/class-ajax.php):

add_action('wp_ajax_nopriv_update_settings', 'sunshine_update_settings');
function sunshine_update_settings() {
    // No capability check
    update_option('sunshine_settings', $_POST['settings']);
    wp_send_json_success();
}

Patched Code (Hypothetical):

add_action('wp_ajax_update_settings', 'sunshine_update_settings');
function sunshine_update_settings() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    update_option('sunshine_settings', $_POST['settings']);
    wp_send_json_success();
}

The patched version removes the nopriv hook (which allows unauthenticated access) and adds a capability check using current_user_can('manage_options').

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with Sunshine Photo Cart <= 3.5.7.1 installed.
• Network access to the target.

Exploitation Steps:

1. Identify vulnerable endpoints by analyzing the plugin's AJAX hooks (e.g., wp_ajax_nopriv_*).
2. Send a crafted POST request to the WordPress admin-ajax.php endpoint.

Example cURL Command:

curl -X POST https://target.com/wp-admin/admin-ajax.php \
  -d "action=update_settings&settings[gallery_visibility]=public"

Expected Outcome: The plugin settings are modified without authentication.

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual AJAX requests to admin-ajax.php with action parameters that match Sunshine Photo Cart hooks.
• Look for requests from unauthenticated users to endpoints that should require admin privileges.

Defense:

• Immediately disable the Sunshine Photo Cart plugin until a patch is available.
• Implement a Web Application Firewall (WAF) rule to block requests to known vulnerable endpoints.
• Use a WordPress security plugin to enforce capability checks on all AJAX actions.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /wp-admin/admin-ajax.php with action=update_settings or similar Sunshine Photo Cart actions.
  • Unusual changes to plugin settings (e.g., gallery visibility, pricing).
• File IOCs:
  • Modified wp_options table entries for sunshine_settings.
• Log IOCs:
  • WordPress debug logs showing unauthorized AJAX calls.

Detection Engineering

YARA Rule

rule Detect_Sunshine_Photo_Cart_Missing_Auth {
    meta:
        description = "Detects exploitation attempts for CVE-2025-68535"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $ajax_hook = "wp_ajax_nopriv_" nocase
        $sunshine_func = "sunshine_" nocase
    condition:
        $ajax_hook and $sunshine_func
}

Sigma Rule

title: Sunshine Photo Cart Missing Authorization Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthorized AJAX requests to Sunshine Photo Cart endpoints
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains: 'action='
        cs-uri-query|contains: 'sunshine_'
    condition: selection
falsepositives:
    - Legitimate admin actions
level: medium

Suricata Rule

alert http any any -> any any (
    msg:"CVE-2025-68535 - Sunshine Photo Cart Missing Authorization Exploitation";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"admin-ajax.php"; http_uri;
    content:"action="; http_client_body;
    pcre:"/sunshine_[a-z_]+/i";
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin – Deactivate and delete Sunshine Photo Cart until a patch is released.
2. Review logs – Check for any unauthorized access to plugin settings.
3. Reset settings – If compromised, restore plugin settings from a known good backup.

Long-term Mitigation:

• Monitor the plugin's official page for updates.
• Consider replacing the plugin with an alternative that has active security support.
• Implement a WordPress security plugin that adds capability checks to all AJAX endpoints.

Vendor Contact: No response received. Users should pressure the vendor via the WordPress plugin support forum.

Valters IT
Securing Digital Frontiers