問題概述

On 3 February 2026 a vulnerability was published that affects the WordPress plugin “Accept Stripe Payments Using Contact Form 7” in versions up to and including 2.5 (CVE-2024-12255). The vulnerability is an unauthenticated information exposure: a public endpoint or code path in the plugin can be invoked by unauthenticated users and returns sensitive configuration or data that should be restricted to site administrators.

The vendor released a fix in version 2.6. The vulnerability is scored at CVSS 5.3 (moderate) and falls under OWASP Top 10 A3: Sensitive Data Exposure. While this does not directly equate to remote code execution, exposed data (API keys, webhook secrets, identifiers) materially increases risk and can lead to fraud or follow-on attacks.

Why this matters for WordPress sites accepting payments

Plugins that integrate payment processors commonly store or reference sensitive items such as:

• API keys (publishable and secret)
• Webhook endpoints and signing secrets
• Payment metadata and customer identifiers
• Configuration revealing internal processing logic

If an attacker obtains API keys or webhook secrets they can:

• Call payment APIs (test or live, depending on key scope)
• Forge webhook requests to inject fraudulent events
• Perform targeted social engineering against customers or support
• Plan further attacks against the site using configuration intelligence

Even exposure of settings or internal IDs significantly raises risk.

Technical description (what “information exposure” generally means)

Information exposure vulnerabilities typically arise when:

• A REST or AJAX endpoint returns data without verifying authentication or nonces.
• A template, admin-ajax action, or short-lived URL is accessible to unauthenticated users and returns debug/config data.
• Plugin code prints or returns serialized options, settings, or environment variables when a crafted request is sent.

In this case, unauthenticated requests could access data that should have been restricted. The vendor addressed the issue in version 2.6 by introducing access checks and removing sensitive fields from unauthenticated responses.

Important: do not seek or share exploit code. Focus on understanding the vector and securing your systems.

誰和什麼面臨風險

At-risk parties include:

• Websites running WordPress with the affected plugin version (≤ 2.5).
• Sites using live Stripe API keys via the plugin.
• Merchants processing payments — potential financial and reputational exposure.
• Hosts, agencies and integrators managing multiple client sites.

If you run version 2.5 or earlier, treat this as a priority: update or mitigate immediately.

立即行動（0–24小時）

1. 確定受影響的網站
   • Log in to each WordPress site and check the plugin version via Dashboard → Plugins → Installed Plugins.
   • Using WP‑CLI: wp plugin get accept-stripe-payments-using-contact-form-7 --field=version
2. 更新插件（首選）
   • Update to version 2.6 or later as soon as feasible. Test in staging before production where possible.
3. Revoke and rotate Stripe keys if you suspect exposure
   • Rotate secret keys in the Stripe Dashboard (Developers → API keys) and update the plugin with new keys.
4. 檢查可疑活動
   • Review server and application logs for unusual requests to plugin paths or endpoints.
   • Look for unexpected API calls from unknown IPs, sudden request spikes, or unauthorized admin changes.
5. Apply immediate access restrictions (short-term)
   • Block or deny public access to known vulnerable endpoints until patched (examples below).
6. 通知利益相關者
   • Notify internal security, site owners, and payment reconciliation teams to monitor for suspicious charges.

如果您無法立即更新 — 短期緩解措施

If an upgrade to 2.6 is not possible within 24 hours, apply these mitigations as stopgaps:

• Deactivate the plugin temporarily: wp plugin deactivate accept-stripe-payments-using-contact-form-7
• Return 403 for requests to the plugin directory via web server configuration (this disables the plugin):

location ~* /wp-content/plugins/accept-stripe-payments-using-contact-form-7/ {
  return 403;
}

Note: blocking the entire plugin folder disables functionality; only use if acceptable.

• Restrict access to endpoints by IP at reverse proxy layer where feasible.
• Temporarily remove or unregister REST routes contributed by the plugin via a WordPress filter (example below).
• Harden and preserve logs for forensic purposes.

// Example PHP filter to temporarily unregister plugin REST endpoints
add_filter( 'rest_endpoints', function( $endpoints ) {
    foreach ( $endpoints as $route => $data ) {
        if ( strpos( $route, 'accept-stripe-payments-using-contact-form-7' ) !== false ) {
            unset( $endpoints[ $route ] );
        }
    }
    return $endpoints;
});

These are temporary measures; installing the official patched plugin is the permanent fix.

WAF guidance and virtual patching (vendor‑neutral)

A Web Application Firewall (WAF) or reverse-proxy controls are useful to block probing and to virtual‑patch known request patterns while you update. Below are vendor-neutral guidance and example patterns. Adapt to your platform and test before deployment to avoid disrupting legitimate traffic.

High-level rules to consider:

• Block unauthenticated requests to plugin-specific REST endpoints and admin endpoints that return JSON configuration.
• Require a logged-in session or valid WordPress nonce for endpoints that should be authenticated.
• Rate-limit and block scanners probing plugin paths.

Example ModSecurity-style rule (pattern-based):

SecRule REQUEST_URI "@rx /wp-content/plugins/accept-stripe-payments-using-contact-form-7/.*" \
  "id:1001001,phase:1,deny,log,msg:'Blocked request to vulnerable plugin path',severity:2"

Example WAF logic (pseudo):

• If request URI contains plugin slug AND request method is GET or POST AND no WordPress auth cookie present, then block or challenge (CAPTCHA).
• If repeated rapid accesses to plugin paths, rate-limit and deny.

Virtual patches are a bridge only. Remove temporary rules once the plugin is updated and verified.

Detection: what to look for in logs and WordPress state

Search for indicators that may point to probing or exploitation:

• Requests containing the plugin folder name: /wp-content/plugins/accept-stripe-payments-using-contact-form-7/
• 請求到 admin-ajax.php, wp-json/ endpoints, or plugin-specific routes from unusual IPs
• Requests including terms like “settings”, “options”, “config”, “api_key”, “stripe” in URIs or query strings
• Unexpected 200 responses returning long JSON payloads with configuration data
• Sudden spikes of requests to plugin endpoints from the same IPs

示例日誌查詢：

grep -i "accept-stripe-payments-using-contact-form-7" /var/log/nginx/access.log
grep -i "wp-json" /var/log/nginx/access.log | grep -i "stripe\|accept-stripe\|contact-form-7"

WP‑CLI checks:

wp plugin get accept-stripe-payments-using-contact-form-7 --field=version
wp option get asp_settings  # replace with actual option name if known

Incident response checklist (if you suspect targeting or compromise)

1. 遏制
   • Update the plugin to 2.6 (preferred) or deactivate it immediately.
   • Apply WAF or webserver rules denying public access to affected endpoints.
2. Protect accounts and keys
   • Rotate Stripe API keys and webhook secrets.
   • Reset WordPress admin passwords and enforce strong, unique credentials.
   • Invalidate active sessions where appropriate.
3. Preservation & logging
   • Preserve webserver, WAF, application and database logs. Export to a secure offline location.
4. 調查。
   • Identify timeframe of suspicious requests. List IPs, user agents, and payloads.
   • Check for new admin users, dropped files, modified themes/plugins, or unusual cron jobs.
5. Eradication & recovery
   • Remove malicious artifacts or restore from a known-clean backup.
   • Reinstall the patched plugin from official sources and verify operation.
6. Notification & reporting
   • Assess whether legal or regulatory notification is required for exposed data.
   • Contact payment processor support if fraudulent transactions are observed.
7. 事件後回顧
   • Document lessons learned and strengthen controls (monitoring, patching cadence, WAF rules).

Hardening measures to prevent similar exposures

Recommended long-term controls:

• Keep WordPress core, themes and plugins updated; maintain a patching schedule.
• Enforce least privilege and use role-based access control.
• Use restricted API keys when possible (Stripe supports scoped keys).
• Store secrets in environment variables or secure vaults rather than in public files.
• Minimise plugin count to reduce attack surface.
• Enable file integrity monitoring and continuous logging.
• Require nonces and capability checks for custom endpoints.
• Enforce 2FA for administrative accounts and strong password policies.
• Run regular vulnerability and malware scans.

Practical examples: searches, commands and safe rules

Safe, non-exploitative checks you can run to assess exposure. Back up and test before applying changes.

1. 檢查插件版本：

   wp plugin get accept-stripe-payments-using-contact-form-7 --field=version

2. Search server logs:

   grep -i "accept-stripe-payments-using-contact-form-7" /var/log/nginx/access.log
   grep -i "accept-stripe-payments-using-contact-form-7" /var/log/apache2/access.log

3. Search REST calls:

   grep -i "wp-json" /var/log/nginx/access.log | grep -i "stripe\|accept-stripe\|contact-form-7"

4. Example ModSecurity signature:

   SecRule REQUEST_URI "@contains accept-stripe-payments-using-contact-form-7" \
     "id:1002001,phase:1,deny,log,msg:'Blocking public access to known vulnerable plugin path',severity:2"

5. Example PHP filter to unregister REST endpoints (temporary):

   add_filter( 'rest_endpoints', function( $endpoints ) {
       foreach ( $endpoints as $route => $data ) {
           if ( strpos( $route, 'accept-stripe-payments-using-contact-form-7' ) !== false ) {
               unset( $endpoints[ $route ] );
           }
       }
       return $endpoints;
   });

6. Stripe key rotation procedure (typical steps):
   • Create a new key in Stripe Dashboard → Developers → API keys.
   • Update plugin configuration with the new key.
   • Confirm the new key works, then revoke the old key.
   • Rotate webhook signing secret by recreating or updating the webhook.

建議的修復時間表

• Within 1 hour: Identify affected sites, enable increased logging, and consider key rotation if exposure is suspected.
• Within 24 hours: Apply WAF rules or deactivate plugin if you cannot update immediately.
• Within 48–72 hours: Update plugin to 2.6 and verify functionality.
• Within 7 days: Complete incident review, rotate additional credentials if necessary, and document actions.

Final thoughts — pragmatic, localised perspective

Plugins that touch payments require heightened vigilance. The fix is straightforward: install the vendor’s patched release. However, the practical risk window begins at public disclosure — automated scanners and opportunistic attackers often probe quickly.

For site owners and administrators in Hong Kong and the region: maintain a rapid patching workflow, ensure appropriate logging retention (useful for local regulatory response), and keep lines of communication open with payment reconciliation and finance teams to detect fraud quickly.

Minimise plugin bloat, enforce privilege separation, and maintain the ability to roll out protective rules at scale. These operational measures materially reduce the chance that a single plugin issue becomes a business incident.

關於作者

This advisory was prepared by a Hong Kong-based security expert with experience in WordPress security, incident response and pragmatic risk reduction for merchants. The guidance above reflects practical mitigation and response steps suitable for site owners, hosts and integrators operating in the Greater China and APAC markets.

Appendix: resources and next steps (quick checklist)

• Check plugin versions (WP Dashboard or WP‑CLI)
• Update plugin to 2.6 or later
• Rotate Stripe keys if you suspect any exposure
• Apply temporary rules blocking plugin paths until update is installed
• Search logs for plugin-related activity and preserve evidence
• Scan the site for malware and unauthorized changes
• Enable continuous monitoring and enforce a patching runbook

If you require professional assistance with WAF rules, log analysis, or recovery from suspected compromise, engage a trusted security professional or incident response team. Prioritise containment, evidence preservation, and credential rotation.