CVE-2025-47526

Executive Summary

CVE-2025-47526 is a Missing Authorization vulnerability in the GS Variation Swatches for WooCommerce WordPress plugin (versions up to and including 3.0.4). This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized data exposure or modification of WooCommerce product variation settings. The vulnerability resides in the WordPress ecosystem and does not affect the underlying Apache or Nginx infrastructure. With a CVSS score of 5.4 (Medium), it poses a moderate risk, particularly for e-commerce sites relying on this plugin for product display customization.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. No OSV or GitHub advisory data is available, indicating limited public disclosure. The plugin is not an NPM, PyPI, Go, or Ruby package, but its inclusion in a WordPress site introduces supply chain risk if the plugin is not updated or removed.

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): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited data modification.
• Availability (A): None (N) – No denial-of-service impact.

Threat Level: Medium. The low EPSS score (0.0%) suggests limited active exploitation, but the lack of a patch increases risk for unmanaged installations.

Deep Dive & Mechanics

The vulnerability stems from missing authorization checks in the plugin's AJAX handlers or REST API endpoints. The plugin likely exposes functions to manage product variation swatches (e.g., colors, images) without verifying user capabilities. An unauthenticated attacker can send crafted HTTP requests to these endpoints, bypassing WordPress's built-in current_user_can() checks.

Root Cause: The plugin fails to implement proper capability checks (e.g., manage_woocommerce or edit_products) before executing sensitive operations. This allows any remote user to:

• Read or modify swatch settings.
• Access product variation metadata.
• Potentially inject malicious swatch data.

Attack Vector: Direct HTTP requests to endpoints like /wp-admin/admin-ajax.php?action=gs_swatch_action or custom REST routes.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code pattern is inferred:

Vulnerable (<= 3.0.4):

add_action('wp_ajax_nopriv_gs_swatch_update', 'gs_swatch_update_handler');
function gs_swatch_update_handler() {
    // Missing capability check
    $swatch_data = $_POST['swatch'];
    update_option('gs_swatch_settings', $swatch_data);
    wp_send_json_success();
}

Patched (Hypothetical):

add_action('wp_ajax_gs_swatch_update', 'gs_swatch_update_handler');
function gs_swatch_update_handler() {
    if (!current_user_can('manage_woocommerce')) {
        wp_die('Unauthorized', 403);
    }
    $swatch_data = $_POST['swatch'];
    update_option('gs_swatch_settings', $swatch_data);
    wp_send_json_success();
}

The patch removes the nopriv suffix (which allows unauthenticated access) and adds a capability check.

Exploitation & Lab Setup

Red Team (Proof of Concept)

Since no public exploit exists, craft a manual exploit:

# Exploit: Unauthenticated swatch modification
curl -X POST http://target.com/wp-admin/admin-ajax.php \
  -d "action=gs_swatch_update&swatch[color]=red" \
  -H "Content-Type: application/x-www-form-urlencoded"

Lab Setup:

1. Install WordPress 6.x with WooCommerce and GS Variation Swatches 3.0.4.
2. Identify AJAX actions via plugin source code (e.g., gs_swatch_update, gs_swatch_get).
3. Send unauthenticated POST requests to modify swatch data.

Blue Team (Detection & Hardening)

• Monitor AJAX requests: Log all admin-ajax.php calls with action parameters.
• Harden plugin: Disable the plugin if not critical, or apply a virtual patch via WAF.
• Audit capabilities: Ensure only authorized roles can access WooCommerce settings.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /wp-admin/admin-ajax.php with action=gs_swatch_* from unauthenticated sources.
• File: Modified wp_options table entries containing gs_swatch_settings.
• Log: WordPress debug logs showing wp_ajax_nopriv_* hooks triggered without authentication.

Detection Engineering

YARA Rule

rule CVE_2025_47526_GS_Swatches {
    meta:
        description = "Detects vulnerable GS Variation Swatches plugin files"
        author = "Valters IT"
        date = "2025-04-10"
        hash = "unknown"
    strings:
        $vuln_func = "wp_ajax_nopriv_gs_swatch" nocase
        $vuln_hook = "add_action('wp_ajax_nopriv_gs_swatch" nocase
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-47526 - Unauthenticated GS Swatches AJAX Access
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthenticated AJAX requests to GS Variation Swatches endpoints
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains|all:
            - 'action=gs_swatch'
            - 'swatch'
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: medium

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-47526 - Unauthenticated GS Swatches AJAX Access";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"admin-ajax.php"; http_uri;
    content:"action=gs_swatch"; http_client_body;
    content:"swatch"; http_client_body;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

1. Immediate: Disable the GS Variation Swatches plugin until a patch is released.
2. Virtual Patching: Use a WAF to block requests to admin-ajax.php with action parameters containing gs_swatch from unauthenticated sources.
3. Code Fix: Add current_user_can('manage_woocommerce') checks to all AJAX handlers and remove nopriv hooks.
4. Monitoring: Enable WordPress audit logging and monitor for unauthorized AJAX calls.
5. Alternative: Replace the plugin with a secure alternative that implements proper authorization.

Valters IT
Securing WordPress Ecosystems