プラグイン名	Soledad
Type of Vulnerability	認証されていないリモートコード実行
CVE Number	CVE-2025-8105
緊急	中くらい
CVE Publish Date	2025-08-16
Source URL	CVE-2025-8105

Soledad Theme (≤ 8.6.7) — Unauthenticated Arbitrary Shortcode Execution (CVE-2025-8105)

まとめ： A recently disclosed vulnerability in the Soledad WordPress theme (versions up to and including 8.6.7) allows unauthenticated attackers to perform arbitrary shortcode execution, enabling content injection on affected sites. The issue is tracked as CVE-2025-8105 and carries a CVSS score of 7.3 (Medium). Theme authors released a fix in Soledad 8.6.8; administrators should update immediately. This post explains the technical risk, how to detect signs of exploitation, remediation options including virtual patching with WP-Firewall, and recommended incident response and hardening measures.

Important: If your site uses the Soledad theme and you cannot update immediately, follow the mitigation steps below and consider adding virtual patching via WP-Firewall to block exploitation attempts until you can update.

---

Table of contents

• What “arbitrary shortcode execution” means
• Why this matters: real-world impact
• Technical overview of the vulnerability (safe, high-level)
• Indicators of compromise (what to look for)
• Immediate remediation (patching and short-term mitigations)
• Virtual patching with WP-Firewall — how we protect you
• WAF rule guidance (conceptual & safe examples)
• Post-compromise response and cleanup checklist
• Detection techniques and useful WP-CLI / SQL checks
• Long-term hardening and operational recommendations
• WP-Firewall Basic (Free) plan — how it helps your site
• Summary and final recommendations

---

What “arbitrary shortcode execution” means

Shortcodes are a WordPress mechanism that lets content creators insert interactive or dynamic content into posts/pages using a textual placeholder like:

[example_shortcode attr="value"]

A shortcode is mapped to PHP code (a handler) that runs when WordPress renders content. Arbitrary shortcode execution means an attacker — without being authenticated — can craft a request that causes the site to evaluate and run shortcodes that the attacker controls or injects. In practice, this can be abused to:

• Inject content into pages or posts (content injection),
• Insert shortcodes that call other plugin or theme functionality,
• Place phishing pages or spam content,
• Potentially trigger unexpected code paths that lead to information disclosure or other side effects.

Because shortcodes can be powerful and call into many parts of a site, allowing unauthenticated execution is a serious misconfiguration or coding bug.

---

Why this matters: real-world impact

While the CVSS score is “Medium”, the real-world impact can be significant:

• Content injection can be used to host phishing pages on a trusted domain (very effective social engineering).
• Injected shortcodes may interact with third-party plugins in unexpected ways (e.g., generating cached pages with malicious content, triggering outgoing requests, or exposing private endpoints).
• Because the vulnerability is unauthenticated, it scales: attackers can automate probing and mass-exploitation campaigns.
• Search engines and blacklist services can mark a site as malicious, resulting in traffic loss and hours of remediation work.

Time matters. Exploit code for vulnerabilities like this is often weaponized quickly after public disclosure. If you run a Soledad site (≤ 8.6.7), update the theme immediately or implement virtual patches to block attacks.

---

Technical overview of the vulnerability (high-level and safe)

The root cause of this vulnerability is that certain code paths in the theme accept untrusted input and subsequently call shortcode evaluation routines (for example, WordPress’ do_shortcode or functions that execute dynamic shortcodes) without sufficient sanitization, context checks, or capability restrictions. Because those code paths are reachable by unauthenticated requests, an attacker can inject content containing shortcodes or trigger the evaluation of shortcodes supplied by the attacker.

Important: This summary intentionally avoids showing exploit proof-of-concept code or exact request patterns that would aid attackers. Our focus is on detection and safe mitigation.

Key contributing factors common to shortcode execution vulnerabilities:

• Accepting and processing user-provided content (GET/POST parameters, REST endpoints, AJAX) with no input validation.
• Executing shortcodes or content via do_shortcode or similar functions inside endpoints that do not check authentication or nonces.
• Lack of escape/sanitization before storing or rendering injected content.

---

Indicators of compromise (IOCs): what to look for

If an attacker has exploited the vulnerability, you may see one or more of the following signs:

• Unexpected content appearing on public pages (phishing text, spam links, iframes).
• New posts/pages or changes to existing posts with unfamiliar shortcodes in their content (look for square bracket patterns like “[… ]”).
• Unusual POST/GET requests in access logs targeting theme endpoints (look for repeated requests or payloads containing shortcode-like tokens).
• User reports of pages looking different, or site content being flagged by browsers or search engines.
• Newly added scheduled posts (wp_posts entries with post_status = 'future').
• Alerts from security scanners showing new modified files or suspicious content.

Collect logs and snapshots for forensics before making content changes to ensure you understand scope and root cause.

---

Immediate remediation (what to do right now)

1. Update the theme
   • The vendor released Soledad 8.6.8 which fixes the issue. Update to 8.6.8 (or later) immediately in a safe maintenance window.
   • If you have a child theme, test updates in staging first.
2. If you cannot update immediately, apply temporary mitigations:
   • Block access to known vulnerable endpoints (see “Virtual patching” below).
   • Harden input handling at the web application level (WAF): block requests containing suspicious shortcode payloads that target endpoints not meant to accept arbitrary content.
   • Disable or restrict any public endpoints added by the theme that accept content parameters.
3. Check and clean content:
   • Search posts and pages for suspicious shortcodes or new content. Remove or revert any injected content.
   • If you must quarantine the site to stop further damage, place it behind maintenance mode.
4. Reset credentials:
   • Rotate admin passwords and keys if you suspect broader compromise (especially if a malicious admin user was created or if wp-users were modified).
5. Take forensic snapshots:
   • Export wp_posts, wp_options, and file system snapshots for later analysis and evidence.

---

Virtual patching with WP-Firewall — how we protect you

At WP-Firewall we provide managed virtual patching that can be deployed immediately to stop exploitation attempts while you apply vendor fixes. Virtual patching does not change theme code — instead it blocks malicious requests at the edge.

What our virtual patching does for this vulnerability:

• Blocks HTTP requests that contain payload patterns used to inject shortcodes into vulnerable endpoints, reducing the attack surface.
• Adds strict request validation for endpoints associated with the theme, rejecting content that contains suspicious shortcode syntax, suspicious HTML payloads, or large content fields coming from unauthenticated sources.
• Monitors and logs attempted exploitation attempts and presents them clearly in the dashboard so you can prioritize and respond.
• Offers heuristics and signature-based rules that match the behavior of shortcode injection attempts, while minimizing false positives.

Why this helps:

• Reduces risk immediately for sites that cannot update the theme right away.
• Buys time to test and roll out an update safely.
• Provides visibility into the scale and timing of attacks.

---

WAF rule guidance (conceptual and safe examples)

Below are conceptual examples of WAF matching patterns and logic you can use to block attacks related to arbitrary shortcode injection. These are intentionally high-level and safe: avoid dropping legitimate traffic.

1. Block suspicious content submissions containing shortcode markers coming from unauthenticated endpoints:
   • Pattern to detect: requests with body or query-string containing “[” followed by an alphanumeric token and “]” (e.g., [shortcode]).
   • Only enforce this rule for endpoints that should not accept user content (theme AJAX endpoints, specific PHP files) and for unauthenticated sessions.

   Example (pseudo-rule, not production copy):

   • If request path matches /wp-admin/admin-ajax.php または /wp-json/your-theme-endpoint そして
   • Request method is POST or PUT and
   • Request body contains regex \[[a-zA-Z0-9_:-]+\b.*?\] そして
   • No valid WordPress nonce or cookie session indicating an authenticated admin,
   • Then block or challenge (403 or CAPTCHA) the request.
2. Rate-limit and fingerprint:
   • Add rate limits to unauthenticated requests that include shortcode-like patterns to prevent brute-force mass injection.
3. Protect REST endpoints:
   • For REST endpoints that accept content, require authentication or valid nonces and block bodies that include suspicious PCM (potential content markers) like shortcodes or base64-encoded content from unauthenticated sources.
4. Monitor without blocking (audit mode first):
   • Roll out new rules in monitor (log) mode for 24–48 hours to measure false positive rates before enforcing.

Note: Use these rules as guidance. WP-Firewall provides managed rules that we tune for you to reduce false positives and protect your site instantly.

---

Post-compromise response and cleanup checklist

If you find evidence of exploitation, follow this step-by-step incident response checklist:

1. Isolate & snapshot
   • Take a full backup (files + database) for forensics.
   • Put the site into maintenance mode if public exposure is severe.
2. Block live exploitation vectors
   • Apply WP-Firewall virtual patch or equivalent WAF rule to block further attacks.
   • Revoke or rotate any compromised credentials.
3. Inventory changes
   • Check wp_posts for injected content or new pages:
     • Search for suspicious shortcodes or unfamiliar HTML.
   • Check wp_オプション for unfamiliar autoloaded options.
   • 検索 wp_ユーザー for new admin accounts.
4. Clean the content
   • Remove injected shortcodes and malicious content, or restore clean versions from a known-good backup.
   • If attack added files, compare file tree to backups and remove unfamiliar files.
5. Scan and repair files
   • Use a trusted malware scanner to locate suspicious modifications.
   • Replace modified core/theme/plugin files with clean copies from official sources.
6. Validate integrities
   • Check checksums/hashes for core/theme/plugin files where possible.
   • Re-scan the site after cleanup.
7. Reissue credentials and keys
   • Reset admin passwords, API keys, OAuth tokens, and any SSO or external access tokens.
8. Patch & update
   • Upgrade the theme to 8.6.8 or later.
   • Update all plugins and WordPress core to latest stable releases.
9. Post-incident monitoring
   • Keep enhanced logging, WAF rules, and monitoring for at least 30 days.
   • Consider external review or professional incident response for severe cases.
10. Disclosure & SEO recovery
    • If phishing or spam content caused blacklisting, follow search engine and security provider delisting steps after cleanup.

---

Detection techniques: WP-CLI, SQL and log queries

Here are practical checks you can run to detect suspicious content or evidence of exploitation.

Search posts for shortcodes (WP-CLI):

List posts containing square bracket patterns:

# List all posts and grep for posts that contain '[' in post_content
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%[%]%';"

More specific: find posts containing the string “[” followed by letters (simple SQL regex depends on DB support):

# On MySQL 8+ (REGEXP)
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content REGEXP '\\[[[:alpha:]]+';"

Find recently modified posts:

# Show posts modified in the last 30 days
wp post list --post_type=post,page --post_status=publish --format=csv --field=ID,post_title,post_modified | awk -F, '$3 >= strftime("%Y-%m-%d", systime() - 30*24*3600)'

Search the database for new admin users:

wp user list --role=administrator --format=csv

Search file system for suspicious shortcodes in theme and uploads:

# Search for shortcode-like patterns in uploads or theme folders
grep -R --exclude-dir=node_modules --exclude-dir=.git -n "\[[a-zA-Z0-9_:-]\+" wp-content/themes wp-content/uploads

Check web server logs:

• Look for unusual POST requests to /wp-admin/admin-ajax.php, /wp-json/*, or theme-specific endpoints.
• Filter for requests that include ‘[‘ or ‘shortcode’ strings in query parameters or bodies.

Note: Always save copies of logs before cleaning.

---

Long-term hardening and operational recommendations

To reduce the risk of similar issues in the future:

• Keep everything updated: core, themes, plugins. Apply vendor updates promptly.
• Limit theme/plugin footprint: remove unused themes and plugins. Even inactive code can be weaponized if misconfigured.
• Enforce the principle of least privilege for users.
• Use strong credentials and multi-factor authentication for admin users.
• Turn off file editing in wp-admin:

  // Add to wp-config.php
  define('DISALLOW_FILE_EDIT', true);
  define('DISALLOW_FILE_MODS', false); // optional: prevent plugin/theme updates from admin if you use other deployment mechanism
  

• Protect key endpoints:
  • Restrict wp-admin and sensitive endpoints by IP (where feasible).
  • Protect admin-ajax endpoints with nonces and logged-in checks for high-risk operations.
• Implement logging and file integrity monitoring to detect unauthorized changes quickly.
• Maintain regular backups and periodically test restore procedures.
• Vet third-party themes and plugins: prefer well-maintained, actively supported solutions.
• Use a Web Application Firewall (WAF) that supports virtual patching and granular rule control.

---

WP-Firewall Basic (Free) plan — Protect your site now

Title: Start defending your site with WP-Firewall Basic (Free)

If you’re looking for an immediate, no-cost layer of protection while you patch or investigate, WP-Firewall Basic (Free) gives you essential protection right away. The Basic plan includes a managed firewall, unlimited bandwidth, a web application firewall (WAF) designed to stop common injection attacks, a malware scanner, and mitigation for OWASP Top 10 risks. It’s designed to be light-weight, fast to deploy, and effective at blocking automated exploitation attempts like those targeting the Soledad shortcode issue.

Sign up and enable Basic protection here:
https://my.wp-firewall.com/buy/wp-firewall-free-plan/

If you want added automation (automatic malware removal and IP control), consider Standard; for monthly security reports, auto vulnerability virtual patching, and premium add-ons like a dedicated account manager and managed services, see our Pro tier.

---

Why virtual patching matters (and when to use it)

Vendor patches are the definitive fix. But realities such as customizations, staging cycles, or delayed vendor updates can make immediate patching impractical. Virtual patching is a practical bridge:

• It blocks known exploit patterns at the edge.
• It reduces the attack surface until you can safely apply the permanent fix.
• It produces logs and telemetry that support forensics.

Use virtual patching as part of a layered defense strategy — not as a replacement for code fixes.

---

Frequently asked questions

Q: If I update to Soledad 8.6.8, am I safe?
A: Updating to 8.6.8 (or later) removes the specific vulnerability. After updating, you should still verify that no malicious content was injected before the update and run a malware scan and integrity checks. Also confirm there are no residual backdoors or added admin users.

Q: Can WP-Firewall break my site with virtual patch rules?
A: Our managed rules are tested to minimize false positives. We recommend deploying new rules in monitoring mode first, then enabling enforcement after confirming no legitimate traffic is impacted. If needed, WP-Firewall supports whitelisting to quickly unblock legitimate flows.

Q: What if I already see phishing pages hosted on my domain?
A: Follow the incident response checklist: isolate, snapshot, block ongoing attacks with a WAF, remove malicious content (or restore from clean backup), rotate credentials, reissue API keys, and then request delisting from search engines/security providers after cleanup.

---

Final recommendations and summary

• If your site uses the Soledad theme and the version is ≤ 8.6.7, update to 8.6.8 or later immediately.
• If you cannot update right away, enable virtual patching via a WAF and follow the short-term mitigations above.
• Search your content and logs for indicators of compromise, and follow the incident response checklist if you detect malicious activity.
• Employ a layered security posture: keep everything updated, restrict access, enable monitoring and backups, and use a managed firewall to block emerging threats while you remediate.

Security is a process, not a one-off task. Vulnerabilities appear frequently; reducing the time between disclosure and protection significantly lowers your risk. WP-Firewall offers solutions (including a free Basic plan) to give you immediate coverage, virtual patching if code fixes are delayed, and escalation options for organizations that need managed services and reporting.

Stay safe, and if you need help implementing any of the recommendations above, WP-Firewall support is available to assist with virtual patching, tuning rules, and performing a post-incident review.

---

If you’d like a tailored checklist or help creating specific WAF rules for your environment, reach out to WP-Firewall support and we’ll guide you through implementation and testing.