CVE-2025-49241

Executive Summary

CVE-2025-49241 is a Missing Authorization vulnerability in the WordPress plugin oik by Bobbingwide, affecting versions through 4.15.1. 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 is classified as Medium Severity with a CVSS score of 5.3, and as of this report, no patch is available. Given the WordPress ecosystem context, this issue could impact sites using the oik plugin for content management and shortcodes.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users should verify the integrity of their plugin files and monitor for updates from the vendor. No known supply chain compromise has been reported, but the lack of a patch increases risk.

CVSS Breakdown & Threat Level

• CVSS Score: 5.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low
• Integrity Impact: None
• Availability Impact: None

The threat level is Medium due to the low complexity and no required privileges, but the impact is limited to confidentiality.

Deep Dive & Mechanics

The vulnerability resides in the oik WordPress plugin, which provides shortcodes and content management features. The missing authorization check occurs in one or more AJAX handlers or REST API endpoints that fail to verify user capabilities before processing requests. An attacker can send crafted HTTP requests to these endpoints to access data or perform actions intended for authenticated users.

The core issue is a Missing Authorization (CWE-862) where the plugin does not enforce proper access controls, allowing unauthenticated users to trigger functions that should require specific permissions.

Vulnerable vs. Patched Code

Since no patch is available, we can only analyze the vulnerable code pattern. The vulnerable version likely contains code similar to:

// Vulnerable: No capability check
add_action('wp_ajax_nopriv_oik_action', 'oik_handle_action');
function oik_handle_action() {
    // Process request without checking user capabilities
    $data = $_POST['data'];
    // ... sensitive operation
}

A patched version would include:

// Patched: Capability check added
add_action('wp_ajax_oik_action', 'oik_handle_action');
function oik_handle_action() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized');
    }
    $data = $_POST['data'];
    // ... sensitive operation
}

Exploitation & Lab Setup

Red Team

To exploit this vulnerability, an attacker can send a crafted HTTP request to the vulnerable endpoint. Since no public exploit code is available, a generic approach is:

curl -X POST http://target.com/wp-admin/admin-ajax.php \
  -d "action=oik_action&data=malicious_payload"

Lab Setup:

1. Install WordPress with the oik plugin version 4.15.1.
2. Identify the vulnerable AJAX action by reviewing plugin source code.
3. Send unauthenticated requests to trigger the missing authorization.

Blue Team

To detect exploitation attempts:

• Monitor for unusual AJAX requests to admin-ajax.php with action parameters related to oik.
• Look for requests from unauthenticated users to endpoints that should require authentication.
• Implement Web Application Firewall (WAF) rules to block suspicious patterns.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /wp-admin/admin-ajax.php with action=oik_* parameters from unauthenticated sources.
• File: Modified or unexpected files in /wp-content/plugins/oik/ directory.
• Log: WordPress debug logs showing unauthorized access attempts to oik functions.

Detection Engineering

YARA Rule

rule CVE_2025_49241_oik_Missing_Auth {
    meta:
        description = "Detects vulnerable oik plugin files with missing authorization"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-49241"
    strings:
        $vuln_func = "wp_ajax_nopriv_oik" nocase
        $vuln_pattern = "add_action('wp_ajax_nopriv_" nocase
    condition:
        $vuln_func or $vuln_pattern
}

Sigma Rule

title: CVE-2025-49241 - Missing Authorization in oik Plugin
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated AJAX requests to oik plugin endpoints
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=oik_'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate plugin functionality if misconfigured
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-49241 - oik Plugin Missing Authorization Attempt"; flow:to_server; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=oik_"; http_client_body; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable the oik plugin until a patch is available.
2. Short-term: Implement a Web Application Firewall (WAF) rule to block unauthenticated requests to oik AJAX endpoints.
3. Long-term: Monitor the vendor's website for a patched version and apply it promptly.
4. Workaround: If the plugin is essential, restrict access to admin-ajax.php using .htaccess or server-level authentication.

Valters IT
Securing Digital Frontiers