Unauthenticated Arbitrary File Download in “PDF Generator Addon for Elementor Page Builder” (CVE-2024-9935) — What WordPress Site Owners Must Do Right Now

Date : February 2026
Auteur : Expert en sécurité de Hong Kong

Résumé

A critical vulnerability (CVE-2024-9935) affects the “PDF Generator Addon for Elementor Page Builder” (versions ≤ 2.0.0). An unauthenticated attacker can request and download arbitrary files from an affected site. This exposes configuration files, backups, database dumps and any other data accessible under the web server account. Treat this as high priority if you run WordPress with this plugin installed.

Table des matières

• Ce qu'est la vulnérabilité (niveau élevé)
• Pourquoi cela importe — scénarios de risque dans le monde réel
• Technical summary (safe, non-exploitable)
• How attacks are typically carried out (abuse patterns)
• Immediate mitigation checklist (what to do in the next 1–2 hours)
• Patch, update and validation (next 1–7 days)
• WAF-based mitigations and virtual patch suggestions
• Log indicators and how to detect past exploitation
• If you suspect compromise — incident response steps
• Long-term hardening & operational recommendations
• How rapid virtual patching and managed protections help
• Practical examples and templates
• FAQ
• Appendices: quick checklist

Ce qu'est la vulnérabilité (niveau élevé)

CVE-2024-9935 is an unauthenticated arbitrary file download vulnerability in the PDF Generator Addon for Elementor Page Builder plugin (versions ≤ 2.0.0). The plugin exposes an endpoint that accepts a file path or identifier and returns the requested file. Insufficient input validation and missing access controls allow an attacker to request files outside the intended directory using traversal sequences or absolute paths — no authentication required.

Pourquoi cela importe — scénarios de risque dans le monde réel

Arbitrary file download vulnerabilities are high-risk because an attacker can directly obtain sensitive files, for example:

• wp-config.php — database credentials, salts, secret keys
• Backup archives stored on disk (.zip, .sql) — full site source and databases
• Logs containing usernames, emails or other metadata
• Private keys or SSH configuration files if stored in web-accessible locations
• User-uploaded files that should be private (legal documents, invoices, etc.)

With database credentials attackers may access or exfiltrate the database; with backup files they can analyze your site offline to find API keys and other secrets. The impact can be immediate and severe: data breach, privilege escalation and persistent compromise.

Technical summary (safe, non-exploitable)

• Vulnerable component: PDF Generator Addon for Elementor Page Builder plugin
• Versions affectées : ≤ 2.0.0
• Fixed in: 2.0.1 (upgrade recommended)
• CVE: CVE-2024-9935
• Type: Arbitrary file download due to broken access control / insufficient input validation
• Privilèges requis : Aucun (non authentifié)
• Gravité : Élevée

In short: an HTTP endpoint accepts a filename parameter that is not sanitized or restricted, allowing traversal sequences (../) or absolute paths to return arbitrary files.

How attacks are typically carried out (abuse patterns)

1. Reconnaissance — attackers probe for the plugin by checking plugin URLs, JS/CSS or known endpoints.
2. Endpoint discovery — enumeration and fuzzing of parameters that serve files (e.g., ?file= or ?doc=).
3. Path traversal attempts — supplying ../ or absolute paths to climb outside allowed directories.
4. Targeting high-value filenames — requesting wp-config.php, backups (*.zip, *.sql), /etc/passwd, etc.
5. Automation — once a working pattern is found, attackers mass-scan many sites to harvest data.

Liste de vérification pour une atténuation immédiate (premières 1–2 heures)

1. Identify plugin presence: WP admin → Plugins → confirm whether “PDF Generator Addon for Elementor Page Builder” is installed and which version.
2. If version ≤ 2.0.0, prioritize containment:
   • Update to 2.0.1 or later immediately if possible.
   • If you cannot update right away, deactivate the plugin from WordPress admin or rename its folder via SFTP/SSH (wp-content/plugins/<plugin-folder>) to take it offline.
3. If you must keep the plugin active, apply server-level or WAF-based blocking as a temporary measure (examples below).
4. Scan access logs for suspicious download requests (see detection section).
5. If you have reason to suspect data exposure, place the site into maintenance mode and proceed with incident response steps (preserve logs, rotate credentials, etc.).

Patch, update and validation (next 1–7 days)

1. Update the plugin to version 2.0.1+ via Dashboard → Plugins or via CLI/composer where applicable.
2. Verify the update: confirm plugin files were replaced and review the changelog/patch notes.
3. Test functionality in staging (PDF generation and dependent features) before enabling in production.
4. Remove temporary mitigations (renamed folders, server blocks) after update and verification, unless you decide to keep them.
5. Validate remediation by performing benign traversal tests in a staging environment to ensure unauthorized files are not returned.

WAF-based mitigations and virtual patch suggestions

A Web Application Firewall (WAF) or server-side rules can buy time by blocking exploit attempts until you can patch. The following patterns are defensive and should be tested in staging before production use.

Principles for rules

• Fail-closed: block suspicious requests and allow known-good payloads.
• Combine pattern matching, rate limiting and IP reputation where available.
• Prefer allowlists for allowed file extensions and known safe paths rather than attempting to blacklist every potential payload.

Recommended rule patterns (examples)

• Block path traversal sequences: ../, ..\ or encoded variations (%2e%2e).
• Restrict file-serving endpoints to allowed extensions — if the plugin is only meant to serve PDFs, permit only .pdf requests.
• Deny attempts to access sensitive filenames: wp-config.php, .env, id_rsa, *.sql, *.zip, backup, etc.
• Block null-byte injection patterns (%00) and suspicious path separators.
• Require authentication or valid referer for admin-style endpoints where applicable.
• Rate-limit file-serving endpoints to mitigate automated large-scale harvesting.

Example server-level block (nginx)

location ~* /wp-content/plugins/pdf-generator-addon/ {
    set $deny 0;
    if ($arg_file ~* "\.\./|\.\.\\|%2e%2e|%00") { set $deny 1; }
    if ($request_uri ~* "(wp-config\.php|\.env|id_rsa|\.sql|\.zip|backup)") { set $deny 1; }
    if ($deny = 1) { return 403; }
}

Example .htaccess block (Apache)

<IfModule mod_rewrite.c>
  RewriteEngine On
  RewriteCond %{QUERY_STRING} (\.\./|\.\.\\|%2e%2e|%00) [NC,OR]
  RewriteCond %{QUERY_STRING} (wp-config\.php|\.env|id_rsa|\.sql|\.zip|backup) [NC]
  RewriteRule ^ - [F]
</IfModule>

Notes: test these patterns in staging. Adjust plugin-specific paths and parameter names as needed. If you use a cloud WAF, create targeted virtual-patch rules for the plugin’s file-serving endpoint.

Log indicators — how to detect attempted or successful exploitation

Search for the following in web and application logs:

• Requests to plugin-specific endpoints (plugin slug or known file-serving routes).
• Query parameters containing ../, %2e%2e, %00 or absolute paths (starting with /home, /var, /etc).
• Requests for high-value filenames: wp-config.php, *.sql, *.zip, .env, id_rsa, etc.
• 200 responses returning binary files where normally JSON or HTML is expected — check Content-Type headers (application/octet-stream, application/x-gzip, text/x-sql).
• Unusual user-agents or rapid repeated requests from a single IP (automation fingerprints).
• Follow-up actions from the same IP such as login attempts or other reconnaissance.

How to search logs (practical queries)

grep -E "wp-content/plugins/pdf-generator-addon|pdf-generator" access.log | grep -E "(\.\./|%2e%2e|wp-config\.php|\.env|\.sql|\.zip|backup)"

If you discover suspicious activity, archive logs immediately and proceed to incident response.

If you suspect compromise — incident response steps

1. Isolate — consider taking the site offline or enabling maintenance mode if active exploitation is occurring.
2. Preserve evidence — export and securely store webserver, plugin and database logs for forensic review.
3. Confirm exposure — determine which files were downloaded using logs and response codes; document the scope.
4. Rotate keys and credentials — change WordPress admin passwords, database passwords, API keys and any credentials found in exposed files. Rotate third‑party keys if they appear in exposed content.
5. Search for and remove backdoors — run malware scans and perform a manual code audit for unknown files or web shells.
6. Restore from clean backup if necessary — if you cannot confidently clean the site, restore from a known-good backup made before the compromise. Verify backup integrity.
7. Reassess hosting environment — audit filesystem permissions and discuss potential lateral movement with your hosting provider.
8. Rebuild secrets and certs — regenerate WordPress salts, rotate TLS/SSH keys and update any credentials that might have been exposed.
9. Post-incident reporting — if personal data was exposed, comply with applicable breach-notification obligations and inform stakeholders as required.

Long-term hardening & operational recommendations

• Gardez le cœur de WordPress, les thèmes et les plugins à jour.
• Use a WAF and enable virtual patching where available for rapid mitigation of zero-days.
• Enforce least-privilege on servers and apply strict file permissions; avoid world-writable files.
• Avoid storing backups in web-accessible directories; use off-site or authenticated storage.
• Regularly audit installed plugins and remove any not actively used.
• Implement allowlist approaches for file-serving endpoints — only allow exact paths or sanitized basenames.
• Use separate credentials per environment and avoid credential reuse across sites.
• Activer l'authentification multi-facteurs (MFA) pour les comptes administrateurs.
• Maintain regular automated backups with offline retention and test restore procedures.
• Monitor logs and set alerts for suspicious file-access patterns (many 200 responses returning binaries, traversal attempts).
• Harden PHP settings (disable allow_url_include, restrict open_basedir where feasible).

How rapid virtual patching and managed protections help

Rapid virtual patching (rules deployed at the edge or in a WAF) reduces exposure window while administrators apply permanent fixes. Typical benefits:

• Blocks common exploitation patterns (traversal, suspicious filenames) before they reach the vulnerable code.
• Allows time to schedule safe updates and testing in staging.
• Can be combined with rate limiting and IP reputation to reduce mass automated harvesting.

Virtual patches are a mitigation, not a replacement for vendor fixes — apply the vendor patch as soon as possible.

Practical examples and templates you can use right now

1) Quick server block for traversal attempts (nginx)

# Block obvious traversal and sensitive file requests for plugin area
location ~* /wp-content/plugins/pdf-generator-addon/ {
    if ($args ~* "(\.\./|\.\.\\|%2e%2e|%00|wp-config\.php|\.env|id_rsa|\.sql|\.zip|backup)") {
        return 403;
    }
}

2) WordPress health checklist (short)

• Update the plugin to 2.0.1+.
• Deactivate the plugin if update is not possible immediately.
• Run a malware scan across files.
• Search logs for suspicious downloads and preserve evidence.
• Rotate credentials if sensitive files were exposed.
• Review and enable protective rules (WAF or server-level) while patching.

3) Query to find suspicious downloads in logs

# Example grep (adjust paths)
zgrep -E "pdf-generator-addon|pdfgenerator|pdfgen" /var/log/nginx/access.log* | grep -E "(\.\./|%2e%2e|wp-config\.php|\.env|\.sql|\.zip|backup)"

Pourquoi la protection en couches est importante

Zero-day threats are a race: attackers attempt exploitation as soon as vulnerabilities are publicised. Administrators may not be able to patch instantly. A layered approach — allowlists, WAF/virtual patching, patching, monitoring, backups and incident readiness — is the practical defence against large-scale automated attacks and targeted compromises.

FAQ — questions courantes

Q: If I update to 2.0.1, am I safe?

Updating to 2.0.1 addresses the known vulnerability. After updating, verify the patch in a staging environment and continue monitoring logs for unusual activity. Remain vigilant for signs of prior compromise.

Q: Can I perform an in-place hotfix to my copy of the plugin?

Local code fixes are possible if you understand the plugin flow, but modifying plugin code carries risk: vendor updates can overwrite fixes and custom changes may introduce regressions. Best practice: apply the vendor patch, test in staging, and use WAF virtual patching as a safe short-term mitigation.

Q: Does blocking public access to wp-config.php help?

Yes. Proper server configuration should never serve wp-config.php as a static file. Ensure backups and configuration files are not stored in web-accessible locations. Do not rely on obscurity alone.

Q: Should I remove the plugin?

If you do not use the plugin’s functionality, uninstall it. Unused or abandoned plugins are common attack vectors.

Remarques de clôture

This vulnerability underscores that WordPress security is ongoing maintenance and risk management. Prompt patching is the primary remediation, but practical defence relies on layered protection: secure configuration, continuous monitoring and edge protections that can be deployed quickly when required.

If you require assistance auditing logs, deploying targeted rules, or conducting incident response, contact your hosting provider or a qualified security professional for hands-on support.

Stay vigilant and act quickly — keep WordPress components up to date.

Appendix A — Quick checklist (one page)

• Identify plugin and version.
• Update to 2.0.1+ or deactivate the plugin immediately.
• If unable to update, apply blocking rules for traversal and sensitive filenames.
• Search logs for traversal strings and downloads of sensitive filenames; preserve logs.
• If exposure suspected: preserve evidence, rotate credentials, run a full malware scan, consider restore from a clean backup.
• Remove the plugin if unused. Harden server file permissions and backup storage.
• Engage a security professional if you need forensic review or remediation assistance.