CVE-2025-31546

Executive Summary

CVE-2025-31546 is a Missing Authorization vulnerability in the WordPress plugin Swiss Toolkit For WP by WP Messiah. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized access to sensitive information or functionality. The vulnerability affects all versions up to and including 1.4.0. As of this report, no official patch has been released, and no public proof-of-concept (PoC) code is available. The CVSS score is 4.3 (Medium), and the EPSS probability is 0.0%, indicating low exploitation likelihood at this time.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. Users who have installed the plugin from the WordPress dashboard or via direct download are affected. The lack of a patch means that supply chain risk is elevated, as no fix is available to mitigate the issue. Administrators should consider disabling the plugin until a patch is released.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Base Score: 4.3 (Medium)
• Attack Vector: Network (AV:N) – The vulnerability can be exploited remotely.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – The exploit does not affect other components.
• Confidentiality Impact: Low (C:L) – Limited information disclosure.
• Integrity Impact: None (I:N) – No data modification.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: Medium. While the impact is limited to low confidentiality, the ease of exploitation (no authentication, low complexity) makes it a viable target for automated scanning and low-sophistication attackers.

Deep Dive & Mechanics

The vulnerability stems from a Missing Authorization check in the Swiss Toolkit For WP plugin. The plugin likely exposes certain REST API endpoints or AJAX actions that perform sensitive operations (e.g., retrieving configuration data, accessing logs, or modifying settings) without verifying that the requesting user has the appropriate capabilities (e.g., manage_options or edit_posts). This allows any unauthenticated visitor to trigger these actions.

The specific affected functionality is not publicly documented, but based on the CWE (CWE-862), the plugin fails to enforce access controls on one or more functions. Attackers can craft HTTP requests to these endpoints to extract information or perform actions that should be restricted to administrators.

Vulnerable vs. Patched Code

Since no patch is available, a direct code comparison cannot be provided. However, the vulnerable code pattern typically looks like:

Vulnerable Code (PHP):

add_action('wp_ajax_nopriv_swiss_toolkit_get_config', 'swiss_toolkit_get_config');
function swiss_toolkit_get_config() {
    // No capability check
    $config = get_option('swiss_toolkit_settings');
    wp_send_json($config);
}

Patched Code (Hypothetical):

add_action('wp_ajax_nopriv_swiss_toolkit_get_config', 'swiss_toolkit_get_config');
function swiss_toolkit_get_config() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    $config = get_option('swiss_toolkit_settings');
    wp_send_json($config);
}

The fix would involve adding a capability check (e.g., current_user_can('manage_options')) before executing sensitive operations.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with Swiss Toolkit For WP <= 1.4.0 installed and activated.
• No authentication required.

Exploitation Steps:

1. Identify the vulnerable endpoint. Common patterns include /wp-admin/admin-ajax.php?action=swiss_toolkit_* or custom REST routes.
2. Send a crafted HTTP request to the endpoint without any authentication cookies.
3. Observe the response for sensitive data or unauthorized actions.

Example Request (Hypothetical):

curl -X POST "http://target.com/wp-admin/admin-ajax.php" \
  -d "action=swiss_toolkit_get_config"

Expected Output:

{
  "api_key": "sk_live_xxxx",
  "debug_mode": true,
  "admin_email": "admin@example.com"
}

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual requests to /wp-admin/admin-ajax.php with action parameters containing swiss_toolkit.
• Look for requests from unauthenticated users (no wordpress_logged_in_* cookie) to sensitive AJAX actions.
• Alert on responses containing plugin configuration data (e.g., API keys, database credentials).

Defense:

• Immediately disable the plugin if no patch is available.
• Implement a Web Application Firewall (WAF) rule to block requests to swiss_toolkit_* actions from unauthenticated users.
• Use a WordPress security plugin to enforce capability checks on all AJAX endpoints.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP POST requests to /wp-admin/admin-ajax.php with action=swiss_toolkit_* parameters.
  • Responses containing JSON objects with keys like api_key, swiss_toolkit_settings, or debug_mode.
• File IOCs:
  • Modified plugin files (e.g., wp-content/plugins/swiss-toolkit-for-wp/).
  • Unexpected files in the uploads directory.
• Log IOCs:
  • WordPress debug log entries showing unauthorized access attempts to plugin functions.
  • Web server access logs with 200 responses to /wp-admin/admin-ajax.php from unknown IPs.

Detection Engineering

YARA Rule

rule CVE_2025_31546_Swiss_Toolkit_For_WP {
    meta:
        description = "Detects exploitation attempts of CVE-2025-31546 in Swiss Toolkit For WP"
        author = "Valters IT"
        date = "2025-04-17"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-31546"
    strings:
        $ajax_action = "swiss_toolkit_" nocase
        $admin_ajax = "/wp-admin/admin-ajax.php" nocase
        $unauthorized = "Unauthorized" nocase
    condition:
        $ajax_action and $admin_ajax and not $unauthorized
}

Sigma Rule

title: CVE-2025-31546 Swiss Toolkit For WP Unauthorized Access
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects unauthenticated requests to Swiss Toolkit For WP AJAX endpoints
author: Valters IT
date: 2025-04-17
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        c-uri|contains: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=swiss_toolkit_'
    condition: selection
falsepositives:
    - Legitimate admin requests (should have authentication cookie)
level: high

Suricata Rule

alert http any any -> any any (
    msg:"CVE-2025-31546 Swiss Toolkit For WP Unauthorized AJAX Access";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action=swiss_toolkit_"; http_client_body;
    nocase;
    sid:1000001;
    rev:1;
    reference:cve,2025-31546;
    classtype:attempted-recon;
    priority:2;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released. Navigate to WordPress Admin > Plugins and deactivate "Swiss Toolkit For WP".
2. Review server logs for any signs of exploitation (unusual AJAX requests).
3. Change any exposed secrets (API keys, database passwords) if the plugin was compromised.

Long-term Mitigation:

• Monitor the WordPress plugin repository for an official patch.
• Implement a Web Application Firewall (WAF) with rules to block unauthenticated access to plugin endpoints.
• Apply the principle of least privilege to all WordPress plugins and users.
• Regularly audit plugin code for missing authorization checks.

Patch Status: UNKNOWN / UNPATCHED. No official fix is available as of this report.

Valters IT