CVE-2023-48277

Executive Summary

CVE-2023-48277 is a Missing Authorization vulnerability in the WordPress plugin Super Progressive Web Apps (super-progressive-web-apps), affecting versions through 2.2.21. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized access to sensitive plugin functionalities. The vulnerability has a CVSS score of 4.3 (Medium) and an EPSS score of 0.0%, indicating low exploitation likelihood in the wild. No public proof-of-concept or exploit code is available at this time. The vendor has not released a patch, leaving all installations of the plugin vulnerable.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin ecosystem. WordPress plugins are distributed via the official WordPress Plugin Directory and can be installed directly from the WordPress admin dashboard. The lack of a patch from the vendor means that users must rely on alternative mitigation strategies, such as disabling the plugin or implementing virtual patching via a Web Application Firewall (WAF). The plugin is not distributed via NPM, PyPI, Go, or Ruby registries.

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)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: Low (C:L)
• Integrity Impact: None (I:N)
• Availability Impact: None (A:N)

Threat Level: Medium. The vulnerability is easy to exploit remotely without authentication, but the impact is limited to low confidentiality loss. No integrity or availability impact is expected.

Deep Dive & Mechanics

The vulnerability stems from a Missing Authorization check in the Super Progressive Web Apps plugin. The plugin likely exposes REST API endpoints or AJAX actions that should require administrative privileges but fail to verify the user's capabilities. An unauthenticated attacker can send crafted HTTP requests to these endpoints to access or modify plugin settings, such as service worker configurations, manifest files, or caching rules.

The root cause is the absence of current_user_can() checks or nonce verification in certain plugin functions. This allows any visitor to the site to trigger actions intended only for authenticated administrators.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code remains in all versions <= 2.2.21. The following is a hypothetical example of the vulnerable pattern:

Vulnerable Code (PHP):

add_action('wp_ajax_nopriv_superpwa_save_settings', 'superpwa_save_settings');
function superpwa_save_settings() {
    // Missing authorization check
    update_option('superpwa_settings', $_POST['settings']);
}

Patched Code (Hypothetical):

add_action('wp_ajax_superpwa_save_settings', 'superpwa_save_settings');
function superpwa_save_settings() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized');
    }
    update_option('superpwa_settings', $_POST['settings']);
}

The patched version would require authentication and the manage_options capability, and would use the wp_ajax_ hook (which requires authentication) instead of wp_ajax_nopriv_.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A WordPress site with Super Progressive Web Apps plugin version <= 2.2.21 installed and activated.
• Network access to the target site.

Exploitation Steps:

1. Identify the vulnerable endpoint. Common endpoints include /wp-admin/admin-ajax.php with action superpwa_save_settings or similar.
2. Send a crafted POST request without authentication:

   curl -X POST http://target/wp-admin/admin-ajax.php \
     -d "action=superpwa_save_settings&settings[manifest_name]=Malicious"
   

3. Verify unauthorized access by checking if the settings were modified.

Note: No public exploit code is available; this is a theoretical exploitation scenario.

Blue Team

Detection:

• Monitor for unusual POST requests to /wp-admin/admin-ajax.php with actions related to superpwa.
• Look for requests lacking a valid nonce or authentication cookie.
• Check for changes to the superpwa_settings option in the database.

Hunting:

• Search logs for action=superpwa_ patterns.
• Use the following Sigma rule to detect exploitation attempts.

Indicators of Compromise (IOCs)

• Network:
  • POST requests to /wp-admin/admin-ajax.php with action=superpwa_* parameters.
  • Requests without a valid WordPress nonce (_wpnonce).
• File:
  • Modified wp_options table entries for superpwa_settings.
• Log:
  • PHP error logs showing unauthorized access attempts to plugin functions.

Detection Engineering

YARA Rule

rule CVE_2023_48277_SuperPWA_Missing_Auth {
    meta:
        description = "Detects exploitation attempts of CVE-2023-48277 in Super Progressive Web Apps plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2023-48277"
    strings:
        $action = "superpwa_" nocase
        $ajax = "admin-ajax.php" nocase
    condition:
        $ajax and $action
}

Sigma Rule

title: CVE-2023-48277 SuperPWA Missing Authorization Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated POST requests to WordPress admin-ajax.php with SuperPWA actions
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        c-uri|contains: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=superpwa_'
    condition: selection
falsepositives:
    - Legitimate admin actions (requires authentication)
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-48277 SuperPWA Missing Authorization Exploitation"; flow:to_server,established; http.method; content:"POST"; http.uri; content:"/wp-admin/admin-ajax.php"; http.client_body; content:"action=superpwa_"; nocase; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if not critical to operations.
2. Implement a Web Application Firewall (WAF) rule to block POST requests to /wp-admin/admin-ajax.php containing action=superpwa_ without a valid nonce.
3. Monitor logs for exploitation attempts.

Long-term:

• Replace the plugin with an alternative that is actively maintained.
• Apply virtual patching via WAF until an official patch is released.
• Contact the vendor to request a security update.

Workaround:

• Add the following code to the theme's functions.php to block unauthenticated access:

add_action('init', function() {
    if (defined('DOING_AJAX') && DOING_AJAX && !is_user_logged_in()) {
        $action = $_REQUEST['action'] ?? '';
        if (strpos($action, 'superpwa_') === 0) {
            wp_die('Unauthorized');
        }
    }
});

Valters IT
Securing Digital Frontiers