CVE-2025-49435

Executive Summary

CVE-2025-49435 is a Cross-Site Request Forgery (CSRF) vulnerability in the WordPress plugin Wp Easy Allopass (slug: wordpress-easy-allopass) by vendor Hasina77. This flaw allows an attacker to trick an authenticated administrator into performing unintended actions, such as modifying plugin settings or triggering payment operations, without their consent. The vulnerability affects all versions from n/a through 4.1.1. No patch is currently available, and the vendor has not responded to disclosure attempts. The CVSS score is 4.3 (Medium), with a low EPSS probability of 0.0%, indicating limited active exploitation in the wild. As a WordPress ecosystem issue, this CSRF vector can be chained with other vulnerabilities to escalate privileges or exfiltrate data.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official plugin repository. Users are advised to monitor for updates or consider removing the plugin if not essential. No package manager (NPM, PyPI, Go, Ruby) is involved.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
• Base Score: 4.3 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: Required (UI:R) – victim must click a crafted link or visit a malicious page.
• Scope: Unchanged (S:U)
• Confidentiality Impact: None (C:N)
• Integrity Impact: Low (I:L) – attacker can modify plugin settings or trigger actions.
• Availability Impact: None (A:N)

Threat Level: Medium. Exploitation requires social engineering, but the impact is limited to integrity compromise within the plugin’s context.

Deep Dive & Mechanics

The CSRF vulnerability in wordpress-easy-allopass arises from missing or improper nonce validation in administrative actions. The plugin likely exposes endpoints (e.g., admin-post.php or AJAX handlers) that perform state-changing operations without verifying a CSRF token. An attacker can craft a malicious HTML page or email that, when visited by an authenticated admin, triggers a forged request to change plugin settings, reset configurations, or initiate payment transactions.

Root Cause: The plugin fails to implement WordPress nonce checks (wp_verify_nonce()) or other anti-CSRF mechanisms in its admin-facing functions. This allows cross-origin requests to be processed as legitimate.

Attack Flow:

1. Attacker identifies a vulnerable action (e.g., wp_easy_allopass_save_settings).
2. Attacker crafts a malicious link or form that submits a POST/GET request to the vulnerable endpoint.
3. Victim (authenticated admin) clicks the link or visits the attacker’s page.
4. The request is executed with the victim’s session, altering plugin state.

Vulnerable vs. Patched Code

Since no patch exists, the vulnerable code is assumed to lack nonce verification. A patched version would include:

Vulnerable (hypothetical):

function wp_easy_allopass_save_settings() {
    // No nonce check
    update_option('wp_easy_allopass_settings', $_POST['settings']);
}
add_action('admin_post_wp_easy_allopass_save', 'wp_easy_allopass_save_settings');

Patched (hypothetical):

function wp_easy_allopass_save_settings() {
    if (!isset($_POST['_wpnonce']) || !wp_verify_nonce($_POST['_wpnonce'], 'wp_easy_allopass_nonce')) {
        wp_die('CSRF validation failed.');
    }
    update_option('wp_easy_allopass_settings', $_POST['settings']);
}
add_action('admin_post_wp_easy_allopass_save', 'wp_easy_allopass_save_settings');

Exploitation & Lab Setup

Red Team

Prerequisites: A WordPress site with the vulnerable plugin installed and an authenticated admin session.

Exploit Steps:

1. Identify the vulnerable endpoint (e.g., via source code review or fuzzing).
2. Create an HTML page that auto-submits a form to the endpoint:

<html>
<body>
<form action="http://target/wp-admin/admin-post.php" method="POST">
  <input type="hidden" name="action" value="wp_easy_allopass_save">
  <input type="hidden" name="settings[api_key]" value="attacker_key">
  <input type="submit" value="Click me">
</form>
<script>document.forms[0].submit();</script>
</body>
</html>

3. Host the page and send the link to the victim (e.g., via phishing email).
4. Once the victim visits, the plugin settings are overwritten.

Note: No public exploit code is available; this is a conceptual demonstration.

Blue Team

Detection & Prevention:

• Monitor for unusual admin-post.php requests with missing or invalid nonce parameters.
• Use Web Application Firewall (WAF) rules to block cross-origin requests to admin endpoints.
• Implement Content Security Policy (CSP) headers to restrict form submissions.
• Educate users about phishing and CSRF risks.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /wp-admin/admin-post.php with action=wp_easy_allopass_save and no _wpnonce parameter.
• Logs: WordPress debug log entries showing wp_easy_allopass_save_settings called without nonce.
• File: Modified wp_options table entries for wp_easy_allopass_settings.
• Behavior: Unexpected changes to plugin configuration (e.g., API keys, payment settings).

Detection Engineering

YARA Rule

rule CVE_2025_49435_CSRF_WordPress {
    meta:
        description = "Detects CSRF exploitation attempts against Wp Easy Allopass plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-49435"
    strings:
        $action = "wp_easy_allopass_save" nocase
        $nonce_missing = "wp_verify_nonce" nocase
    condition:
        $action and not $nonce_missing
}

Sigma Rule

title: CVE-2025-49435 CSRF Exploitation Attempt
id: 8a7b3c2d-1e5f-4a6b-9c8d-7e0f1a2b3c4d
status: experimental
description: Detects HTTP requests targeting Wp Easy Allopass admin actions without CSRF token
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'action=wp_easy_allopass_save'
        cs-uri-query|contains: '_wpnonce'
    condition: selection and not cs-uri-query|contains: '_wpnonce'
falsepositives:
    - Legitimate admin actions with nonce
level: medium

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-49435 - CSRF Attempt on Wp Easy Allopass";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-post.php"; http_uri;
    content:"action=wp_easy_allopass_save"; http_client_body;
    pcre:"/^(?!.*_wpnonce).*$/";
    sid:1000001;
    rev:1;
    reference:cve,2025-49435;
    priority:2;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if not critical for operations.
2. Apply a virtual patch using a WAF to block requests to admin-post.php with action=wp_easy_allopass_save and missing _wpnonce.
3. Monitor logs for suspicious admin actions.

Long-term Fix:

• The vendor must implement nonce verification in all admin-facing functions. Since no patch exists, consider forking the plugin or switching to an alternative.

Workaround:

• Add a custom function to your theme’s functions.php to enforce nonce checks:

add_action('admin_post_wp_easy_allopass_save', function() {
    if (!isset($_POST['_wpnonce']) || !wp_verify_nonce($_POST['_wpnonce'], 'wp_easy_allopass_nonce')) {
        wp_die('CSRF validation failed.');
    }
}, 1);

Valters IT
Securing Digital Frontiers