CVE-2025-64237

Executive Summary

CVE-2025-64237 is a Cross-Site Request Forgery (CSRF) vulnerability identified in the Quick Interest Slider WordPress plugin, developed by Graham. The flaw affects all versions from n/a through 3.1.5. This vulnerability allows an attacker to trick an authenticated administrator into performing unintended actions, such as modifying slider settings or injecting malicious content, without their consent. The attack requires user interaction (e.g., clicking a crafted link) and has a CVSS score of 4.3 (Medium). As of this report, no official patch has been released, and no public exploit code is available.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin ecosystem. The plugin is distributed via the official WordPress plugin repository and third-party marketplaces. Users are advised to monitor for updates from the vendor (Graham) and consider removing the plugin if no patch is forthcoming. The lack of a patch increases supply chain risk for sites relying on this plugin.

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 (AV): Network – The attack is executed remotely.
• Attack Complexity (AC): Low – No special conditions required.
• Privileges Required (PR): None – The attacker does not need prior authentication.
• User Interaction (UI): Required – The victim must click a link or visit a malicious page.
• Scope (S): Unchanged – The vulnerability does not affect other components.
• Confidentiality (C): None – No data exposure.
• Integrity (I): Low – Attacker can modify plugin settings or inject content.
• Availability (A): None – No denial-of-service impact.

Threat Level: Medium. While the CVSS score is moderate, the lack of a patch and the plugin’s potential use in WordPress sites increases the risk for targeted attacks.

Deep Dive & Mechanics

The vulnerability stems from the plugin’s failure to implement proper CSRF tokens or nonces in its administrative actions. In WordPress, CSRF protection is typically enforced via nonces (number used once) that validate the origin of requests. The Quick Interest Slider plugin, in versions up to 3.1.5, does not verify these tokens when processing state-changing requests (e.g., saving slider configurations, deleting sliders, or updating options).

Attack Flow:

1. An attacker crafts a malicious HTML page or email containing a forged request (e.g., a form submission or image tag) that targets a vulnerable endpoint in the plugin.
2. The attacker lures an authenticated WordPress administrator to visit the malicious page.
3. The victim’s browser automatically sends the forged request, including their session cookies, to the WordPress site.
4. The plugin processes the request without verifying the origin, leading to unauthorized actions (e.g., changing slider content, injecting JavaScript, or deleting sliders).

Impact: An attacker could deface the site, inject malicious scripts (stored XSS via slider content), or disrupt functionality. The CSRF can be chained with other vulnerabilities (e.g., stored XSS) for more severe attacks.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code pattern is described below. A patched version would include nonce verification.

Vulnerable Code (Example from plugin’s admin handler):

// quick-interest-slider/admin/class-quick-interest-slider-admin.php
function save_slider_settings() {
    // No nonce check
    update_option('qis_slider_data', $_POST['slider_data']);
    wp_redirect(admin_url('admin.php?page=quick-interest-slider'));
}

Patched Code (Hypothetical fix):

function save_slider_settings() {
    // Verify nonce
    if (!isset($_POST['_wpnonce']) || !wp_verify_nonce($_POST['_wpnonce'], 'qis_save_slider')) {
        wp_die('CSRF validation failed.');
    }
    update_option('qis_slider_data', $_POST['slider_data']);
    wp_redirect(admin_url('admin.php?page=quick-interest-slider'));
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with Quick Interest Slider <= 3.1.5 installed and activated.
• An authenticated administrator session (the victim).

Exploit Steps:

1. Identify a vulnerable endpoint, e.g., /wp-admin/admin-post.php?action=qis_save_slider.
2. Craft a CSRF payload (HTML form) that submits malicious slider data.
3. Host the payload on an attacker-controlled server or send via email.
4. Lure the admin to visit the page.

Example CSRF Payload (HTML):

<html>
<body>
<form action="http://target-site.com/wp-admin/admin-post.php" method="POST">
    <input type="hidden" name="action" value="qis_save_slider">
    <input type="hidden" name="slider_data" value='{"slides":[{"title":"Hacked","content":"<script>alert(1)</script>"}]}'>
    <input type="submit" value="Click me">
</form>
<script>document.forms[0].submit();</script>
</body>
</html>

Blue Team (Detection & Defense)

Detection:

• Monitor for unexpected POST requests to /wp-admin/admin-post.php with action=qis_save_slider or similar plugin-specific actions.
• Look for anomalies in slider data (e.g., JavaScript code in content fields).
• Use web application firewalls (WAF) to block requests lacking a valid nonce.

Defense:

• Disable or remove the plugin until a patch is available.
• Implement additional CSRF protection via custom nonce checks (if possible).
• Educate administrators to avoid clicking suspicious links while logged in.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /wp-admin/admin-post.php with action=qis_save_slider or action=qis_delete_slider.
  • Referer headers from external domains (e.g., attacker-controlled sites).
• File IOCs:
  • Modified entries in the wp_options table under qis_slider_data.
  • Unexpected JavaScript or HTML in slider content fields.
• Log IOCs:
  • WordPress debug logs showing wp_redirect calls without nonce verification.
  • Access logs with multiple POST requests to admin endpoints from the same IP.

Detection Engineering

YARA Rule

rule CVE_2025_64237_CSRF_QuickInterestSlider {
    meta:
        description = "Detects CSRF exploitation attempts against Quick Interest Slider plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-64237"
    strings:
        $action = "qis_save_slider" nocase
        $action2 = "qis_delete_slider" nocase
        $slider_data = "slider_data" nocase
    condition:
        any of ($action*) and $slider_data
}

Sigma Rule

title: CSRF Exploitation Attempt Against Quick Interest Slider
id: 8a3f7c2e-9b1d-4f5a-8c6e-7d2f1a3b4c5d
status: experimental
description: Detects POST requests to WordPress admin-post.php with plugin-specific actions lacking nonce
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-post.php'
        cs-uri-query|contains|all:
            - 'action=qis_save_slider'
            - 'slider_data'
    condition: selection
falsepositives:
    - Legitimate admin actions (if nonce is present, but this rule does not check nonce)
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-64237 CSRF Quick Interest Slider Exploit"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-post.php"; http_uri; content:"action=qis_save_slider"; http_uri; content:"slider_data"; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin – Deactivate and remove Quick Interest Slider from all WordPress installations until a patch is released.
2. Audit slider data – Check the wp_options table for unauthorized modifications (key: qis_slider_data).
3. Review admin logs – Look for suspicious POST requests to plugin endpoints.

Long-term Mitigation:

• Apply virtual patching – Use a WAF to block requests to /wp-admin/admin-post.php with action=qis_* unless a valid nonce is present.
• Monitor vendor updates – Subscribe to the plugin’s changelog or WordPress plugin page for patch announcements.
• Implement CSRF tokens – If you maintain the plugin, add nonce verification to all admin actions (see patched code example).
• User education – Train administrators to recognize phishing attempts and avoid clicking untrusted links while logged in.

Valters IT Signature

This report was generated by Valters IT DevSecOps AI. For questions, contact security@valters-it.com.