プラグイン名	デピクタースライダー
脆弱性の種類	認証がありません
CVE番号	CVE-2025-11373
緊急	低い
CVE公開日	2025-11-04
ソースURL	CVE-2025-11373

Depicter Slider (<= 4.0.4) — Broken Access Control Allowing Contributor File Uploads (CVE-2025-11373)

まとめ

• Vulnerability: Broken access control — missing authorization on a file upload endpoint that allows authenticated Contributor-role users to upload “safe” file types.
• Affected plugin: Depicter Slider (Popup and Slider Builder) — versions <= 4.0.4
• Fixed in: 4.0.5
• CVE: CVE-2025-11373
• Severity: Low (CVSS 4.3), but meaningful for multi-user sites where Contributors exist

As maintainers of a WordPress web application firewall and site-protection product, we want to give site owners and administrators a practical, clear breakdown of the issue, the real-world risk, and the steps you should take right now to protect your sites — whether you operate a small multi-author blog, a community site, or a larger multisite network.

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What the vulnerability is (plain language)

This vulnerability is a broken access control issue. An endpoint in the Depicter Slider plugin allowed files of permitted MIME/file types to be uploaded without properly checking whether the caller had the right privileges to perform that action.

In WordPress, the Contributor role is intended to allow users to write and submit content for review but not to publish or perform administrative tasks such as uploading arbitrary media. Because a plugin endpoint did not enforce the correct capability checks, authenticated users with the Contributor role could upload files through the plugin’s functionality even when the site’s default permissions or editor screens would normally prevent that.

The plugin accepts “safe” file types — typically images and other media formats. While the immediate impact is limited because the plugin blocks obviously dangerous file types, several real-world risks still exist and deserve attention.

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Why this matters — risk scenarios

Even though the vulnerability allows only “safe” file types to be uploaded, there are several ways attackers can still benefit:

1. Stored cross-site scripting (XSS)
   • Some image formats can contain metadata (EXIF) or trigger browser behaviors when processed in certain contexts. If the plugin or other parts of your site later render uploaded content into pages without sanitization, attackers can sometimes exploit that to execute JavaScript in the browser of an admin or another user.
2. Privilege escalation via indirect paths
   • A Contributor who can upload images could later use social engineering or other plugin functionality to get those files included in templates or posts in ways that elevate the impact.
3. Abuse of trusted upload channels
   • File uploads through plugins may be written to locations that are indexed or referenced by the site. If another plugin or theme handles those files insecurely, it can increase attack surface.
4. Local server misconfiguration
   • In edge cases, some servers are misconfigured such that files uploaded with certain filenames or double extensions can be executed. Even if the plugin filters by MIME type, filename parsing bugs or permissive server settings can present execution risk.
5. Reconnaissance and persistence
   • A malicious Contributor can upload content used for covert communication, signaling or host additional assets that later support more complex campaigns.

Because the Contributor role is commonly used on multi-author blogs and community sites, this defect creates an avenue for low-privileged users to perform actions outside their intended privilege set.

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CVE and timeline (public data)

• CVE ID: CVE-2025-11373
• Publicly reported: November 5, 2025
• Affected versions: Depicter Slider <= 4.0.4
• Fixed in: Depicter Slider 4.0.5

Credit: The vulnerability was responsibly disclosed by a security researcher and the plugin was updated to correct the missing authorization check.

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How an attacker could (hypothetically) leverage this

I will not provide exploit code. However, it’s valuable to understand the general chain so defenders can prioritize mitigations:

1. An attacker registers or obtains an account with Contributor-level access (or compromises one).
2. Using the plugin’s upload endpoint, the attacker uploads a crafted file (image/allowed type).
3. The uploaded file gets stored in a path accessible by the application or administrator interfaces.
4. The attacker leverages rendering or other plugin/theme behavior to cause that file to be used in an unsafe context (e.g., injected into an admin preview or included in a post in a way that triggers a browser vulnerability).
5. The attacker uses that capability to perform additional steps: social engineering, stored XSS targeting high-privilege users, or reconnaissance.

注記： Because the highest-risk payloads (executable PHP) are not accepted, immediate remote code execution is less likely — but risk remains for multi-step attacks, particularly in environments with misconfigurations or other vulnerable components.

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Detection — signs your site may be affected

If you run Depicter Slider and have Contributors on your site, treat this as actionable. Signs to check:

• Installed plugin version <= 4.0.4 (first priority check).
• Recent uploads by Contributor users that appear in plugin-specific upload directories.
• Unusual image or media files in the uploads folder with names that look automated or unexpected.
• Administrator or editor reports of unexpected media appearing in the media library or in plugin-managed lists.
• Web server logs showing POST requests to plugin endpoints from Contributor accounts that performed file uploads.

How to quickly check plugin version (WP admin):

• Go to Plugins > Installed Plugins and find “Depicter Slider” — update if it’s older than 4.0.5.

Or via CLI:

• wpプラグインリスト
• wp plugin get depicter –fields=version

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Immediate remediation steps (priority order)

1. Update Depicter Slider to 4.0.5 (or later) — Highest priority
   • The vendor released 4.0.5 which includes the missing authorization checks. Upgrading removes the vulnerability at source.
2. すぐに更新できない場合:
   • Temporarily remove or deactivate the Depicter Slider plugin until you can apply the update.
   • Alternatively, block the plugin’s upload endpoint with your web application firewall (WAF) or by restricting access via webserver rules.
3. Audit accounts with Contributor role
   • Ensure that Contributor accounts are valid, necessary, and monitored.
   • Remove stale or unused contributor accounts.
4. Review recent uploads
   • Inspect the uploads directory and plugin-specific storage areas for recent files by Contributors.
   • Look for suspicious filenames or files that aren’t associated with editorial content.
5. Lock down uploads folder execution
   • Ensure your /wp-content/uploads/ and plugin upload directories are not executable. For Apache, add .htaccess rules to deny execution. For NGINX, ensure PHP handlers are not assigned to uploads paths.
6. Implement stronger capability checks for site editors
   • Where possible, require that users who upload media have capabilities such as upload_files or higher.
7. Enable additional monitoring and alerting
   • Watch for file upload events, user role changes, and new users created with Contributor-like roles.

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Hardening checklist — beyond the fix

• 最小権限の原則
  • Limit the number of users with roles that grant write access. Use role management plugins carefully and avoid granting upload capability to untrusted roles.
• File-type and content validation
  • Plugins should validate both MIME type and file signature and then sanitize filenames. Don’t rely solely on file extensions.
• Sanitize metadata
  • Strip embedded metadata (EXIF) from images if you do not need it.
• Enforce nonces and capability checks
  • Well-designed plugin endpoints must verify WordPress nonces and check user capabilities before performing state-changing actions.
• Server hardening
  • Disable execution of scripts in upload directories (deny .php, .phtml, .php3, etc.). Ensure correct permissions on wp-content and subfolders.
• Monitoring and logging
  • Enable logging for file uploads and maintain a routine review process. Log file upload source and user ID.
• 脆弱性管理
  • Subscribe to vulnerability feeds and apply updates promptly. Keep plugins and the Core updated.

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How to audit your site for compromise (step-by-step)

1. Snapshot the site
   • Take filesystem and database backups before making changes for forensic integrity.
2. Scan for suspicious files
   • Check /wp-content/uploads and plugin-specific folders for unusual files or readme-like files created recently.
3. Check database for injected content
   • Search posts and options for unexpected URLs or inline scripts.
4. Review logs
   • Look at access logs and application logs for POST requests to plugin endpoints from Contributor accounts.
5. Revalidate user accounts
   • Confirm no account escalations or newly created administrator accounts exist.
6. Re-install plugins from trusted sources
   • Where in doubt, delete and reinstall the plugin from the official repository after updating.
7. Consider professional incident response
   • If you find signs of compromise (unauthorized admins, backdoors, unknown scheduled jobs), involve a professional.

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How WP‑Firewall helps protect you (practical mitigation)

As a WordPress firewall vendor, our focus is to stop exploitation chains like this quickly — sometimes even before plugin authors provide a fix. Here are the ways WP‑Firewall helps:

• Managed WAF rules tailored to WordPress plugin endpoints
  • We provide virtual patching rules that block abuse patterns against known vulnerable endpoints such as improper upload endpoints or missing capability checks.
• Malware and content scanning
  • Continuous scanning of uploads and plugin directories to detect anomalies, suspicious file types, and injected content.
• Role-based request filtering
  • Ability to restrict or format checks on requests from authenticated users with contributor-level privileges to prevent abuse of plugin upload endpoints.
• Blocking and logging suspicious upload attempts
  • WAF rules can detect and block suspicious POST requests to plugin endpoints or flag repeated uploads from the same Contributor account.
• Automated alerts and Incident records
  • Timely alerts to admins when patterns matching a vulnerability are observed, together with forensic logs for investigation.
• Hardening guidance and onboarding support
  • Best-practice recommendations and guided setup to ensure uploads directories are not executable and that plugin endpoints are monitored.

If you manage multiple sites, these protections reduce your mean time to mitigate and lower the window where attackers can exploit a vulnerability like this one.

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Recommended WAF rule patterns (conceptual — for defenders)

Below are non-actionable, conceptual rule ideas that mature WAFes can implement to reduce risk from similar broken-access endpoints:

• Block or challenge upload POSTs to plugin upload endpoints unless the request includes:
  • A valid WordPress nonce
  • A user with appropriate capability (upload_files or higher)
• Rate-limit uploads by authenticated users with low-privilege roles (e.g., Contributor)
• Inspect Content-Type and file signatures — drop uploads that mismatch extension and signature
• Monitor for unusual file metadata (long scripts within EXIF) and quarantine files pending review
• Alert when a Contributor account uploads files outside normal editorial flows

These are patterns that a WAF should enforce in addition to the plugin’s own checks. They are defensive layers, not replacements for patching.

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Operational recommendations for agencies and hosts

• Prioritize updating sites with Depicter Slider installed — schedule mass updates and communicate risk to clients.
• Temporarily block plugin upload endpoints at the host edge for client sites where immediate update is not feasible.
• Enforce centrally-managed upload execution prevention (server-level) across all sites.
• Perform client outreach: inform site owners who have multiple contributors about the risk and expected resolution steps.
• Run a one-time sweep for suspicious media files and flagged Contributor activity.

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A developer checklist: fixing similar bugs in your own plugin

• Always verify capabilities for state-changing endpoints:
  • Example: current_user_can(‘upload_files’) and check_admin_referer() or wp_verify_nonce().
• Limit upload endpoints to users who absolutely need them.
• Use esc_url_raw(), sanitize_file_name(), wp_check_filetype_and_ext() and proper MIME checks.
• Consider using wp_handle_sideload() and wp_handle_upload() to leverage WP core sanitization.
• Add integration tests that exercise endpoints with different roles (Subscriber, Contributor, Author, Editor, Admin).
• Avoid relying solely on client-side checks (JavaScript) for authorization.

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Detection rules you can add to your logging/monitoring

• Alert on POSTs to plugin upload endpoints from users whose role is Contributor.
• Alert on more-than-expected upload frequency from the same user (e.g., > 10 uploads/hour).
• Flag uploads with mismatched extension and file signature.
• Detect new files placed directly under plugin directories outside normal plugin flows.

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よくある質問

Q — Is this vulnerability a site-takeover risk?
A — Not directly. The vulnerability allows Contributor-level authenticated users to upload permitted file types. It is classified as low because uploadable types are restricted. However, chained with other vulnerabilities or misconfigurations it could enable more serious outcomes, so address it quickly.

Q — Should I delete Depicter Slider?
A — If you do not use it or cannot update promptly, deactivate and remove the plugin. If it’s essential to your site, update to 4.0.5 immediately and follow the hardening checklist.

Q — I updated the plugin. Do I still need further steps?
A — Yes. After patching, audit recent uploads and user activity, review logs, and ensure server-side hardening is in place.

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Incident response checklist (if you find suspicious uploads)

1. Isolate the site (temporarily reduce access to admin role, disable plugin if needed).
2. Take a forensic backup.
3. Identify all recent uploads by Contributor accounts and review content.
4. Scan site with multiple reputable scanners and manual review.
5. Rotate passwords for affected accounts and consider forced re-authentication for those with Contributor roles.
6. Remove malicious or suspicious files after confirming backups exist.
7. Reinstall a fresh copy of the plugin from the official repository after update.
8. Monitor for resurfacing indicators of compromise.

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Closing guidance — prioritize patching and layered defenses

The Depicter Slider missing authorization issue is a reminder that broken access control errors show up even in well-used plugins. The single most important action is to update the plugin to 4.0.5 or later. After updating, use the steps in this article to harden uploads, audit user accounts, and implement layered protections (WAF, monitoring, proper server configuration).

Even low-severity vulnerabilities can become high-impact if combined with other weaknesses. A defense-in-depth approach — patch early, limit privileges, harden servers, and apply WAF rules — is the best way to protect your WordPress sites.

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Appendix — Quick action checklist (copy-paste)

• ☐ Check plugin version; update Depicter Slider to 4.0.5 or later
• ☐ If you cannot update: deactivate plugin or block plugin upload endpoints
• ☐ Audit Contributor accounts and recent uploads
• ☐ Ensure /wp-content/uploads/ is non-executable
• ☐ Scan site for suspicious files and metadata
• ☐ Enable WAF rules to protect upload endpoints and rate limit Contributor uploads
• ☐ Monitor logs for unusual POST requests caused by low-privilege users
• ☐ Document findings and keep backups before making changes

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If you’d like help applying any of the above mitigations, our WP‑Firewall support team can assist with emergency virtual patching, guided cleanup, and hardening. We’re here to help you keep your sites safe while you patch and rebuild trust.