Urgent: CSRF in “WP Plugin Info Card” (≤ 6.2.0) — What WordPress Site Owners Must Do Now

Par : Expert en sécurité de Hong Kong

Date : 2026-02-17

Résumé : A Cross-Site Request Forgery (CSRF) vulnerability (CVE-2026-2023) affecting the WP Plugin Info Card plugin (versions ≤ 6.2.0) allows an attacker to cause privileged users to unintentionally create arbitrary “custom plugin entries.” The vendor released version 6.3.0 to address the issue. If you manage WordPress sites, read this end-to-end analysis and follow the mitigation checklist immediately.

Table des matières

• Que s'est-il passé (résumé court)
• Technical overview (what CSRF is and how this issue works)
• Impact assessment (threat model and real-world risk)
• Evidence and indicators to look for on your site
• Immediate mitigation steps (patching and configuration)
• WAF / virtual-patching guidance
• Renforcement et prévention à long terme
• Règles de détection et recommandations de journalisation.
• Liste de contrôle de réponse aux incidents (si vous soupçonnez une compromission)
• Managed WAF / security engagement (neutral guidance)
• Questions fréquemment posées (FAQ)
• Appendix: sample WAF rules and quick reference

Que s'est-il passé (résumé court)

On 17 February 2026 a CSRF vulnerability (CVE-2026-2023) was disclosed in the WP Plugin Info Card plugin affecting all plugin versions up to and including 6.2.0. The vendor released version 6.3.0 to address the issue.

At a high level this is a Cross-Site Request Forgery problem: an unauthenticated attacker can craft a web request that, when triggered by a logged-in user with sufficient privileges (for example, an administrator or editor), causes the plugin to create a custom plugin entry without proper server-side authorization or nonce verification. Successful exploitation requires that the privileged user performs an action that triggers the crafted request (for example, by visiting a malicious page or clicking a crafted URL). That user interaction requirement reduces immediate automated mass-exploitation risk, but targeted attacks against administrators remain a real threat.

As security professionals based in Hong Kong, we treat all disclosed vulnerabilities seriously. Below is a practical, technical and prioritized guide you can apply now — whether you host a single blog or manage hundreds of client sites.

Technical overview — CSRF in context

What is CSRF?

• Cross-Site Request Forgery occurs when an attacker gets a victim’s browser to make an authenticated request to a site where the victim is logged in, causing that site to perform actions as the victim (for example changing settings, creating posts, or uploading content). The key deficiency is that the server cannot reliably distinguish legitimate requests initiated via the site UI from forged requests initiated from an attacker-controlled page.

Why this plugin was vulnerable

• The vulnerable plugin exposed an action endpoint (an “entry creation” routine) that did not enforce an adequate CSRF protection mechanism (for instance, missing or incorrectly verified WordPress nonces, or missing capability checks). Without nonce checks and proper capability validation, the server accepted POST (or GET) requests that resulted in object creation in the plugin’s data structures.
• The vulnerability is labeled as requiring “Unauthenticated” privilege in the public report metadata but exploitation requires user interaction by a privileged user (UI:R). That means an unauthenticated attacker can craft the malicious link, but a logged-in admin/editor must perform an action (visit/click) for the exploit to succeed. This makes the vulnerability vector CSRF (attacker forces privileged user to act).

What the attacker can do

• Create arbitrary plugin entries (content entries used by the plugin). Depending on how the plugin exposes and uses those entries, attackers could:
  • Inject content that is displayed in the site UI (potentially used for phishing or social engineering),
  • Persist content that later triggers other application logic,
  • Use the plugin’s UI as an injection point for other attacks (e.g., embedding external links or code that could be abused),
  • Add entries that, when combined with other misconfigurations, might facilitate privilege escalation or data exposure.
• Important: There is no indication this vulnerability by itself allows immediate code execution or database takeover. The severity was assigned as low (CVSS 4.3), reflecting limited direct impact, but combined attack chains or targeted social engineering make mitigation imperative.

Impact assessment and threat model

Qui est à risque ?

• Any WordPress site with the WP Plugin Info Card plugin version ≤ 6.2.0 installed.
• Sites where privileged users (administrators, editors, authors with extended rights) log in and browse the web where they could be lured to click links or visit pages (phishing).
• Multi-site installations and agency-managed sites where many people have elevated privileges.

What an attacker needs

• A crafted web page or link they can get a privileged user to visit or click while logged into the target WordPress site.
• No need to have authenticated access themselves — the attack leverages the victim’s session.

Where risk escalates

• Sites that display plugin entries in public pages without sanitization become vectors for content injection visible to visitors.
• Sites that automatically process plugin entries (for example, sending notifications or external requests) may amplify impact.
• Environments with many privileged users or where administrative accounts are shared or used routinely for browsing untrusted content are more exposed.

Risk summary

• Likelihood of mass automated exploitation: Low (requires user interaction).
• Risk of targeted compromise or defacement: Medium. Targeted social engineering or phishing is feasible.
• Potential for chained attacks: Medium. The vulnerability could be an early-stage vector in a chain that leads to data theft or broader compromise if other weaknesses exist.

What to check right now — evidence and indicators

Before patching or if you suspect exploitation, collect these signals:

1. Plugin change logs and entry tables
   • Check plugin-specific database tables for recently-created entries you don’t recognize (timestamps around public disclosure date).
   • Look at admin UI → plugin entries for any suspicious text or links.
2. Journaux d'activité WordPress
   • Audit logs (if you have them) for actions created by the plugin or unknown activities initiated by admin users at odd times.
   • If you use activity logging plugins, search for requests that created plugin entries and note the user and originating IP.
3. Journaux d'accès au serveur Web
   • Search POST requests hitting WordPress admin endpoints (wp-admin/admin-post.php, admin-ajax.php, plugin-specific endpoints) with suspicious parameters or originating from pages with suspicious referers.
   • Look for unusual requests from remote referers — e.g., POSTs with Referer: maliciousdomain.tld.
4. Browser sessions
   • If a specific admin was targeted, review their browser history for unexpected pages visited around the time suspicious entries were created.
5. Outbound requests
   • Some plugin entry processing triggers outbound web requests. Check for new outbound connections or DNS lookups around the time of suspicious activity.

Indicateurs de compromission (IoCs)

• Newly-created plugin entries with external links, obfuscated HTML, or JavaScript.
• POST requests to admin endpoints with unexpected action parameters.
• Admin user sessions performing actions while the user was active on remote sites.

If you find suspicious evidence, follow the incident response checklist below.

Immediate mitigation — step-by-step

These are prioritized actions you should take right now.

1. Patch the plugin (recommended, highest priority)
   • Update WP Plugin Info Card to version 6.3.0 or later on every site. This is the definitive fix supplied by the plugin author.
   • Test on staging before rolling to production if you have custom integrations.
2. If you cannot patch immediately: apply virtual patching via your firewall or hosting provider
   • Deploy a targeted WAF rule blocking requests that match the plugin’s vulnerable entry endpoint patterns, or block suspicious POSTs that do not include a valid WP nonce/referrer header.
   • Ask your hosting provider or security team for assistance if you do not manage a WAF yourself.
3. Reduce admin exposure
   • Ask administrators to log out of admin accounts when they are not actively managing the site.
   • Avoid using administrator accounts for general browsing.
   • Enable Two-Factor Authentication (2FA) for all privileged accounts.
4. Harden cookies and CSRF defenses
   • Ensure your WordPress authentication cookies use SameSite=Lax or Strict where possible.
   • Confirm your site has proper nonce usage for custom plugin endpoints (developers: add wp_create_nonce and check via check_admin_referer or wp_verify_nonce).
5. Review plugin settings and remove unused plugin features
   • If the plugin exposes public entry-creation endpoints you don’t use, disable or remove those features (or replace the plugin).
6. Surveillez et auditez
   • Increase logging and monitoring for the next 30 days; watch for new plugin entries and unexpected admin actions.

WAF / virtual-patching guidance

If you manage sites and cannot immediately update every installation, virtual patching (WAF rules) provides a fast, low-risk mitigation. Below is a recommended, vendor-agnostic approach your security team can adapt.

High-level WAF strategies

• Block direct POST/GET requests to the plugin’s creation endpoint unless accompanied by a verified admin session and valid referer origin.
• Deny requests where Content-Type is inconsistent with browser-originated forms (for example, block application/json to admin endpoints unless expected).
• Enforce Origin/Referer validation for requests that modify server state: allow same-origin referers only.
• Rate-limit requests to plugin admin endpoints to deter automated exploitation.

Sample rule logic (conceptual)

If REQUEST_URI matches plugin entry-creation endpoint AND REQUEST_METHOD is POST/GET AND HTTP_REFERER is empty or external AND session cookie indicates a logged-in admin context => block or challenge the request.

Testing guidance: Put rules in detect-only mode for 24–48 hours to measure false positives, review logged matches, then flip to blocking after tuning.

Example virtual-patch options (for managed environments)

• Block requests to the vulnerable plugin endpoints when the HTTP origin/referer is not from your site or when the request lacks a valid WordPress nonce in a POST body.
• Block anonymous requests that include “create_entry” or similar action parameters to admin-ajax.php or admin-post.php (pattern-based, tuned to minimize false positives).
• Log and alert on matched blocks; collect client IP, referer, matched rule for investigation.

Use these options as templates and adapt them to your environment. Test on staging before applying to production.

Renforcement et prévention à long terme

This disclosure is a reminder to treat CSRF systematically:

For plugin and theme developers

• Always use WordPress nonces (wp_create_nonce, wp_verify_nonce) on state-changing endpoints.
• Check capability/role permissions (current_user_can) before performing actions.
• Prefer admin-post.php or admin-ajax.php with proper checks rather than exposing custom REST endpoints without protections.

For administrators

• Minimize number of users with admin-level privileges.
• Implement role-based access controls and review users quarterly.
• Adopt 2FA for all admin/editor accounts.
• Avoid shared admin accounts.

For hosting providers and security teams

• Offer automatic plugin updates for critical fixes where possible (with backups).
• Provide managed WAF/virtual patching to customers between disclosure and patch availability.
• Maintain an inventory of plugins and versions to quickly identify exposed instances.

For everyone

• Backup regularly (and verify backups).
• Keep WordPress core, theme and plugin updates on a tested cadence.

Detection rules & logging examples

If you operate your own logging stack (Splunk, ELK, Graylog, etc.), add these search patterns to detect suspicious attempts:

1) Web server logs (Nginx/Apache)

Search for POST requests to admin endpoints with external referers. Example query:

REQUEST_URI ~ "/wp-admin/(admin-ajax.php|admin-post.php)" AND REQUEST_METHOD == "POST" AND NOT HTTP_REFERER ~ ^https?://(yourdomain\.com|www\.yourdomain\.com)

2) WordPress logs (activity logs)

• Look for creation events for plugin entries where the creating user session started recently or from unexpected IPs.

3) WAF logs

• Monitor WAF blocks for rules that match plugin entry creation patterns; investigate high volumes from single IPs or new countries.

4) Database queries

Query plugin table for newly added rows after disclosure date (adjust schema names as needed):

SELECT * FROM wp_wp_plugin_info_entries WHERE created_at > '2026-02-17' ORDER BY created_at DESC LIMIT 50;

Liste de contrôle de réponse aux incidents (si vous soupçonnez une compromission)

If you discover suspicious activity consistent with this vulnerability, follow this prioritized runbook:

1. Préservez les preuves
   • Snapshot logs, export database entries, and record timestamps.
2. Contenir
   • Temporarily disable the vulnerable plugin, or enable a temporary firewall rule to block the specific endpoint.
   • Force log out all admin sessions by changing admin passwords and rotating authentication keys (wp-config.php salts).
3. Éradiquer
   • Apply the official plugin update (6.3.0+).
   • Remove any malicious plugin entries discovered (after confirming they are not benign).
4. Récupérer
   • Restore from a known-good backup if data integrity is in doubt.
   • Rotate credentials used by site services (FTP, hosting control panel, API keys).
5. Notify & follow up
   • Notify impacted users if there was data exposure (follow relevant disclosure policies and regulatory requirements).
   • Review the site for any other indicators of compromise (web shells, new users, scheduled tasks).
6. Post-incident
   • Conduct a post-mortem: what allowed the exploit, how can we prevent similar vulnerabilities, and how effective were the mitigations?

Managed WAF / security engagement (neutral guidance)

If you operate multiple sites or lack in-house security expertise, consider engaging your hosting provider or a trusted security consultancy for:

• Temporary virtual patching (WAF rules) while you deploy vendor updates;
• Assistance with incident response, log collection, and forensics;
• Ongoing monitoring and managed security services tailored to your operational needs.

Choose a provider based on transparent procedures, documented SLAs, and the ability to operate in your jurisdiction (data residency and compliance considerations matter for Hong Kong-based operations).

FAQ — short answers to common questions

Q: Is my site compromised if I had WP Plugin Info Card ≤ 6.2.0 installed?

A: Not necessarily. The vulnerability requires a privileged user to be tricked into taking an action (clicking a link or visiting a malicious page). If no privileged user performed such an action, your site may be safe. Still, patch promptly and review logs.

Q: Can signatures or WAF rules cause false positives?

A: Yes. That’s why you should deploy detection-only monitoring for a short period before switching to blocking. Carefully tune rules to your environment.

Q: Should I uninstall the plugin if I can’t update?

A: If the plugin is non-essential and you cannot update immediately, disabling or uninstalling the plugin is a safe interim measure.

Q: I’m a developer — how do I avoid CSRF bugs?

A: Always use WordPress nonces, verify capabilities with current_user_can, and avoid exposing state-changing operations to unauthenticated endpoints. Use check_admin_referer or wp_verify_nonce on form submissions.

Appendix — sample WAF rules (conceptual examples)

Below are conceptual rule examples to block CSRF-style exploitation patterns. These are illustrative — adapt them to your environment and test before enforcing.

1) Block POSTs to suspected vulnerable endpoint when Referer/Origin is absent or external

# Conceptual ModSecurity rule
SecRule REQUEST_URI "@contains /wp-plugin-info-card/" \
  "phase:2,chain,log,deny,id:100100,msg:'Block potential CSRF to WP Plugin Info Card',severity:2"
  SecRule REQUEST_METHOD "POST" \
  "chain"
  SecRule REQUEST_HEADERS:Referer "!@beginsWith https://yourdomain.com" \
  "t:none"

2) Detect suspicious anonymous create requests to admin-ajax/admin-post

# Detect-only example (logging)
SecRule REQUEST_URI "(admin-ajax\.php|admin-post\.php)" \
  "phase:2,log,pass,id:100101,msg:'Suspicious admin-post/ajax create action',nolog,\
   chain"
  SecRule ARGS_NAMES "@rx (create_entry|create_plugin_entry|wp_create_plugin)" \
  "t:none,log"

3) Rate-limit repeated attempts for the same target URL

# Rate-limiting concept: allow 10 requests per minute from the same IP
SecAction "phase:1,pass,nolog,initcol:ip=%{REMOTE_ADDR}"
SecRule IP:REQ_COUNTER "@gt 10" "phase:2,deny,id:100102,msg:'Rate-limit exceeded for plugin endpoint'"

Important: Replace placeholders (yourdomain.com) and the parameter names with values relevant to your site. These rules are starting points for a security engineer — do not paste into production without staging testing.

Final words — prioritizing safety and resilience

This CSRF disclosure is a reminder that even relatively low-severity vulnerabilities can be important when they involve admin workflows. The fastest path to safety is patching (upgrade to version 6.3.0 or later), combined with virtual-patching on a WAF if you cannot update immediately.

Maintain an accurate inventory, schedule rolling updates, use a layered approach (secure hosts, keep WordPress and plugins updated, enable 2FA), and ensure backups and logs are available. If you do not have internal security resources, engage a trusted provider or your host for temporary virtual patching and incident response.

Legal / responsible disclosure note

This blog provides defensive guidance and non-actionable detection advice. It intentionally avoids providing exploit code or step-by-step attack instructions. If you discover a vulnerability, follow responsible disclosure practices and notify the plugin author and appropriate security channels.