Nome do plugin	Shortcode Button
Type of Vulnerability	Authenticated Stored XSS
CVE Number	CVE-2025-10194
Urgência	Baixo
CVE Publish Date	2025-10-15
Source URL	CVE-2025-10194

Shortcode Button (<= 1.1.9) — Authenticated Contributor Stored XSS (CVE-2025-10194): What Site Owners and Developers Must Do Now

Data: 15 October 2025
Autor: WP‑Firewall Security Team

Resumo: A stored Cross‑Site Scripting (XSS) vulnerability affecting the WordPress Shortcode Button plugin (versions <= 1.1.9) has been assigned CVE‑2025‑10194. Authenticated users with Contributor privileges (and above) can store malicious HTML/JavaScript that will be executed in the context of later site visitors or administrators. There is no official vendor patch available at the time of publication. This post explains the risk, exploitation vectors, how to detect compromise, developer fixes, and immediate mitigations — including practical virtual‑patching via WP‑Firewall — to protect your WordPress sites.

---

Índice

• What is stored XSS and why it matters
• The Shortcode Button vulnerability in plain English
• Threat model: who can exploit this and how
• Potential impact to your site and users
• Quick detection: what to look for on your site now
• Immediate mitigation steps (site owner/operators)
• How WP‑Firewall protects your site (virtual patching and rules)
• Recommended developer fixes and secure coding practices
• Hardening, monitoring, and incident response checklist
• Long term recommendations & closing thoughts
• Secure your site with WP‑Firewall Basic (Free) — get started

---

What is stored XSS and why it matters

Cross‑Site Scripting (XSS) occurs when an attacker can inject malicious client‑side scripts into a web page that other users view. Stored XSS (also called persistent XSS) is the most dangerous variant because the malicious payload is saved on the server (e.g., in the database) and served to multiple users over time. When the victim’s browser executes the injected JavaScript, the attacker can:

• Steal cookies or authentication tokens (session theft)
• Perform actions on behalf of logged‑in users (CSRF via script)
• Display phishing content or misleading UI overlays
• Load external malware, perform redirects, or fingerprint users
• Exfiltrate sensitive data visible to the compromised user

In WordPress, stored XSS often stems from plugins or themes that accept user content (shortcode attributes, options pages, post meta) and echo it without proper sanitization and escaping.

---

The Shortcode Button vulnerability in plain English

The Shortcode Button plugin accepts user input that it later outputs into posts/pages or admin views. A security researcher found that when a user with Contributor privileges (or higher) saves certain data through the plugin, the data is stored in the database and subsequently rendered by the plugin without adequate escaping or sanitization. This allows the saved content to contain HTML or JavaScript that will execute when a visitor opens the page (or an admin views an edited post).

Key facts:

• Affects Shortcode Button plugin versions <= 1.1.9
• Vulnerability type: Stored Cross‑Site Scripting (XSS)
• Required privilege: Contributor (authenticated)
• CVE: CVE‑2025‑10194
• Status at publication: No official vendor fix available

Because contributing users (authors/contributors) are common on multi‑author blogs, LMS sites, membership sites, or community sites, the vulnerability increases the likelihood that an attacker can insert a payload by creating or editing content.

---

Threat model: who can exploit this and how

Attack prerequisites and typical exploitation flow:

1. Attacker has an account on the target WordPress site with at least Contributor privileges. This could be:
   • An account the attacker created by registering (if registration is enabled and automatically assigned Contributor).
   • A compromised or social‑engineered Contributor account.
   • A malicious user given Contributor role by an admin (insider risk).
2. The attacker uses the Shortcode Button UI (or any endpoint provided by the plugin that stores data) to insert malicious content. This could be in:
   • Shortcode attributes that are later rendered raw
   • Custom fields or post meta that the plugin outputs
   • Plugin settings saved to options that are displayed in front‑end templates
3. The plugin stores the data in the database without proper sanitization and outputs it without escaping, leading to script execution in visitors’ browsers.
4. The injected script runs in the context of the vulnerable site. Effects may target:
   • Unauthenticated visitors (defacement, redirect, crypto‑mining scripts)
   • Logged‑in users (role‑escalation attempts, CSRF, session theft)
   • Site administrators (credential theft, backdoor installation)

Because the vulnerability is stored, the malicious payload can persist indefinitely and be delivered to many victims.

---

Potential impact to your site and users

The real impact depends on where the payload is rendered and which users are targeted. Examples:

• If the payload is served only to front‑end visitors: defacement, malicious redirects, popups promoting phishing or ads.
• If the payload is executed in the admin area or author/editor pages: attacker may try to steal cookie‑based admin sessions, change settings, upload backdoors, or create new admin accounts.
• If an attacker combines this with social engineering, they can phish administrators and gain persistent access.

Severity interpretation:
The vulnerability is currently scored in the mid range (CVSS ~6.5). The score factors in the requirement for authenticated access (Contributor). However, in many real world WordPress deployments, Contributor accounts are easy to obtain, and site admins often interact with contributed content — so practical risk can be high for some sites.

---

Quick detection: what to look for on your site now

If you host WordPress sites that use Shortcode Button (<= 1.1.9), perform these checks immediately:

1. Inventory
   • Identify installations with the Shortcode Button plugin.
   • Check installed plugin version (wp‑admin → Plugins). Remove or disable if present and unpatched.
2. User roles and registrations
   • Review users with Contributor or higher roles. Look for unusual accounts (recently created, suspicious emails).
   • If registration is open to the public, consider closing registration or changing default role to Subscriber.
3. Search for suspicious content in posts, postmeta, and options
   • Use a database search for suspicious patterns (e.g., “<script”, “onerror=”, “javascript:”, “document.cookie”, “eval(“, “src=’data:text/javascript”).
   • Example (run on your staging environment or after backing up DB):
     SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%<script%';
SELECT * FROM wp_postmeta WHERE meta_value LIKE '%<script%';
   • Note: Use read‑only searches and safeguard backups. Many safe HTML constructs exist; manual review is required.
4. Check recent edits and creation timestamps
   • Review posts/pages created or edited by Contributor accounts in the last 30 days.
5. Scan files and uploads
   • Look for recently modified plugin or theme files.
   • Scan the uploads directory for suspicious PHP files (indicating post‑exploit backdoors).
6. Web logs
   • Review server and WAF logs for suspicious POST requests to plugin endpoints or admin AJAX calls that reference Shortcode Button inputs.

If you find suspect content, do not edit it directly on a production site without backups and testing — strip the payload in a safe environment, then restore clean content.

---

Immediate mitigation steps (site owners/operators)

If you cannot immediately remove or update the plugin (no fix available), apply these prioritized mitigations:

1. Limit Contributor access temporarily
   • Change default registration role to Subscriber.
   • Downgrade suspicious Contributor accounts or block new ones.
   • If possible, temporarily disable new user registrations altogether.
2. Disable or remove the plugin
   • If plugin functionality is not critical, deactivate and delete it until a fix is available.
3. Sanitize existing content
   • Manually review and clean posts or shortcodes stored by contributors.
   • If you identify injected <script> tags or event‑handler attributes (onerror, onclick, etc.), remove them and replace with sanitized content.
4. Harden editor permissions
   • Use a role management plugin to tighten the Contributor role (remove unneeded capabilities like unfiltered_html if present).
   • Remove unfiltered_html capability from Contributors (if your site previously granted it).
5. Apply Content Security Policy (CSP)
   • Deploy a restrictive CSP to make it harder for injected scripts to load external resources or execute inline scripts. Note: CSP can break site features; test before global rollout.
6. Enable your WAF / virtual patching
   • If you run a site firewall, apply rules blocking common XSS patterns (see next section).
7. Monitor and log
   • Increase logging and alerting for changes to user roles, new user registrations, plugin changes, and content edits.
8. Prepare incident response
   • Back up your database and files now. If you detect compromise, isolate the site, preserve logs, and work with incident responders.

---

How WP‑Firewall protects your site (virtual patching and rules)

At WP‑Firewall we design mitigation workflows for exactly this type of situation: a known plugin vulnerability with no immediate vendor patch. Our approach focuses on virtual patching (WAF rules), targeted detection, and operational controls to reduce the window of exposure.

What WP‑Firewall does for you:

• Managed rule deployment: We can deploy a virtual patch that detects and blocks typical payloads used to exploit stored XSS in the Shortcode Button plugin. Rules are tested to minimize false positives and rolled out quickly to protected sites.
• Context‑aware blocking: Rather than bluntly blocking all script tags (which can break legitimate content), we target patterns most likely to be malicious when coming from Contributor accounts or from plugin endpoints that accept shortcode attributes.
• Granular quarantine: Suspicious POST requests can be logged and blocked while the offending content is quarantined rather than immediately deleted, enabling review and rollback.
• Mitigation of OWASP Top 10 risks: Our Basic (Free) plan includes WAF coverage for common attack classes, including XSS. This provides an immediate safety net while site owners evaluate longer term fixes.
• Auto‑mitigation options (Pro): For sites on our higher tiers, we offer automated virtual patching and removal of obvious malicious JS snippets as an emergency measure.

Recommended WP‑Firewall rule examples (conceptual, non‑proprietary)

• Block POST requests that include script tags or event handlers in parameters submitted to known plugin endpoints:
  • Condition: request path contains “shortcode” or plugin admin endpoints AND POST body contains “<script” OR “onerror=” OR “javascript:” (case‑insensitive)
  • Action: Block (HTTP 403) and log details for review.
• Inline script detection for contributor submissions:
  • Condition: user role = contributor AND POST to /wp‑admin/post.php or /wp‑admin/post‑new.php AND post_content contains “<script” OR “eval(” OR “document.cookie”
  • Action: Return sanitized response to user and alert admins.
• Obfuscated payload detection:
  • Condition: presence of common obfuscation tokens (e.g., base64 decoding functions, unescape(), fromCharCode patterns).
  • Action: Block and escalate.

Note: These are conceptual detection patterns. WP‑Firewall maintains and tunes precise rules to limit false positives while offering strong protection. If you’re running WP‑Firewall, reach out to support and ask for the Shortcode Button virtual patch rule to be enabled immediately.

---

Recommended developer fixes and secure coding practices

If you are a plugin or theme developer, here are specific, practical steps to fix the root cause and harden code against stored XSS:

1. Sanitize on input (save)
   When saving user input, sanitize according to expected type:
   • Plain text: use sanitizar_campo_de_texto()
   • Multi‑line text: use sanitize_textarea_field()
   • HTML with allowed tags: use wp_kses() ou wp_kses_post() with an explicit allowed tags/attributes list
   • URLs: use esc_url_raw() on save

   if ( isset( $_POST['button_label'] ) ) {
       $label = sanitize_text_field( wp_unslash( $_POST['button_label'] ) );
       update_post_meta( $post_id, '_sb_button_label', $label );
   }

2. Escape on output
   Use the proper escaping function when echoing values:
   • esc_html() for HTML text nodes
   • esc_attr() for attribute values
   • esc_url() for URLs

   $label = get_post_meta( $post_id, '_sb_button_label', true );
   echo '<button class="sb-button">' . esc_html( $label ) . '</button>';

3. Use capability checks and nonces
   Verify usuário_atual_pode() for actions that save plugin settings or post meta.
   Usar wp_verify_nonce() for admin form submissions and AJAX endpoints to prevent CSRF.

   if ( ! current_user_can( 'edit_post', $post_id ) ) {
       return;
   }
   if ( ! isset( $_POST['_wpnonce'] ) || ! wp_verify_nonce( $_POST['_wpnonce'], 'sb_save_button' ) ) {
       wp_die( 'Nonce verification failed', 403 );
   }

4. Avoid unfiltered_html for lower roles
   Do not rely on WordPress’s unfiltered_html capability for sanitization; if a site grants it to Contributors, document the risk and recommend changing it.
5. Shortcode handling
   When building shortcodes, always sanitize attributes and escape output:

   function sb_button_shortcode( $atts ) {
       $atts = shortcode_atts( array(
           'label' => '',
           'url'   => '',
       ), $atts, 'sb_button' );
   
       $label = sanitize_text_field( $atts['label'] );
       $url   = esc_url( $atts['url'] );
   
       return '<a class="sb-button" href="/pt/' . $url . '/">' . esc_html( $label ) . '</a>';
   }
   add_shortcode( 'sb_button', 'sb_button_shortcode' );

6. Limit what is stored in options and meta
   If user‑provided content must contain HTML, store a sanitized subset and render via wp_kses() with a whitelist.
7. Review admin UI output
   Always wrap plugin admin echo statements with esc_attr_e(), esc_html_e() ou printf with proper escaping to avoid reflected or stored XSS in admin screens.

By combining sanitization on save and escaping on output, you close the typical stored XSS vector.

---

Hardening, monitoring, and incident response checklist

If you suspect injection or want to harden systematically, follow this checklist:

1. Backups
   Take a complete backup (files + DB) immediately and store it offline.
2. Isolate and review
   If you see suspicious posts, move the site to maintenance mode while cleaning and investigating.
3. Clean content safely
   Edit posts in a staging copy. Remove script tags, suspicious attributes, and obfuscated strings.
4. Rotate credentials
   Reset passwords for admin accounts and any suspected compromised accounts. Force logout sessions.
5. Revoke tokens
   Revoke any API keys or OAuth tokens that are potentially exposed.
6. Scan
   Run a malware and integrity scan for modified files and known indicators.
7. Restore
   If the site is compromised, restore from a clean backup (pre‑compromise), then apply mitigation steps before re‑opening.
8. Notify stakeholders
   If user data might be compromised, follow applicable disclosure legislation and notify users.
9. Post‑incident hardening
   Implement stricter role management, CSP, WAF rules, and periodic content scans.

---

Long term recommendations & closing thoughts

• Reduce attack surface: Remove unused plugins and themes. Keep the plugin count minimal and prefer actively maintained plugins.
• Role hygiene: Review role assignments regularly. Avoid granting Contributor (or higher) privileges to untrusted accounts.
• Defense in depth: Combine sanitization, escaping, WAF rules, and CSP. Each layer protects against gaps in the others.
• Test updates: Apply updates in a staging environment and scan for regression or new vulnerabilities.
• Security as process: Make plugin and theme security part of your development lifecycle. Code review and automated static analysis can detect many class errors (e.g., missing escaping).

This Shortcode Button stored XSS demonstrates how an innocuous UI decision (permitting certain input) becomes a broader site‑security problem. Whether you run a small blog or an enterprise WordPress instance, the steps above will help you triage and reduce risk immediately.

---

Secure your site with WP‑Firewall Basic (Free) — get started

Title: Protect your site now: start with WP‑Firewall Basic (Free)

If you’d like an immediate safety net while you remediate the Shortcode Button vulnerability, WP‑Firewall Basic (Free) provides essential protection that helps block and detect attacks like stored XSS. Our Basic plan includes a managed Web Application Firewall (WAF), OWASP Top 10 mitigations, a malware scanner, and unlimited bandwidth — everything you need to start hardening your site today at no cost.

Why start with Basic (Free)?

• Managed firewall and WAF rules that block common XSS payloads
• Malware scanning to detect suspicious scripts and backdoors
• Rapid virtual patching capability to reduce exposure while you test permanent fixes

Upgrade options are available if you want automatic malware removal, IP blacklists/whitelists, monthly reports, and automated virtual patching across your site fleet.

Sign up and protect your site here:
https://my.wp-firewall.com/buy/wp-firewall-free-plan/

---

If you manage WordPress websites, treat this vulnerability as a reminder that plugin inputs must be treated as untrusted. Use the mitigation steps in this post now: inventory affected sites, secure user roles, scan for suspicious content, and enable virtual patching or WAF protections. If you run WP‑Firewall, contact our support team and ask that the Shortcode Button virtual patch be applied to your site immediately. If you need assistance auditing or cleaning an impacted site, our security team is available to help.

Stay safe and keep your plugins tight — the smallest misstep can become a persistent problem if not handled proactively.

— WP‑Firewall Security Team