Tên plugin	Crypto Payment Gateway with Payeer for WooCommerce
Loại lỗ hổng	Payment bypass
Số CVE	CVE-2025-11890
Tính cấp bách	Cao
Ngày xuất bản CVE	2025-11-04
URL nguồn	CVE-2025-11890

Urgent: Protect Your WooCommerce Store from the CVE-2025-11890 Payment Bypass in “Crypto Payment Gateway with Payeer for WooCommerce” (<= 1.0.3)

Ngày: 2025-11-04
Tác giả: Nhóm bảo mật WP-Firewall

Bản tóm tắt

A critical Broken Access Control vulnerability (CVE-2025-11890, CVSS 7.5) impacts the “Crypto Payment Gateway with Payeer for WooCommerce” WordPress plugin (versions <= 1.0.3). The issue allows unauthenticated attackers to mark orders as paid (payment bypass) without any valid payment notification from the payment processor. This enables attackers to deliver digital goods, unlock accounts or downloads, and cause financial reconciliation chaos for merchants.

This post — written from the perspective of WP-Firewall (a WordPress firewall vendor and security provider) — explains the technical root cause, realistic exploitation scenarios, detection indicators, practical mitigations (including virtual patching/WAF rules you can apply immediately), recommended incident response actions for WooCommerce merchants, and secure development guidance for plugin authors.

Ghi chú: If you use the affected plugin, take action immediately. If you do not have time to perform a full patching and testing cycle, follow the short-term mitigations below to reduce risk instantly.

Who should read this

• WooCommerce store owners using any Payeer/crypto payment integrations.
• WordPress administrators and hosting providers managing WooCommerce stores.
• Site security teams responsible for incident response and fraud detection.
• Developers maintaining payment gateway plugins or implementing webhook handlers.

Tổng quan về lỗ hổng

• Loại lỗ hổng: Broken Access Control — unauthenticated payment bypass
• Phần mềm bị ảnh hưởng: Crypto Payment Gateway with Payeer for WooCommerce plugin
• Các phiên bản dễ bị tấn công: <= 1.0.3
• CVE: CVE-2025-11890
• Mức độ nghiêm trọng: High — CVSS 7.5
• Required privileges to exploit: Unauthenticated (no account required)
• Official fix: Not available at time of disclosure (N/A)
• Disclosure date: 4 November 2025

What went wrong (technical overview)

Payment gateway plugins typically expose endpoints (webhooks / IPNs / return handlers) that the payment processor calls to notify your shop about completed payments. A secure webhook implementation should:

• Verify the authenticity of the incoming request (signature, HMAC, token, shared secret).
• Confirm the payment details (order ID exists, amount matches, currency correct).
• Validate that the request came from the payment provider (IP allowlist or signature).
• Check idempotency (prevent replay or duplicate marking).

In this case, the plugin’s notification/validation routine lacks adequate authorization checks and/or fails to verify provider signatures and payment details properly. That means a crafted HTTP request to the plugin’s incoming-notification URL (the server-side handler that normally processes Payeer callbacks) can be accepted as a valid payment notification even though it is not from Payeer. The plugin then marks the associated WooCommerce order as “paid” or “completed” — without a valid payment.

Because the attack requires no authentication, it’s trivial to automate and scale. Once exploited, attackers can:

• Receive digital downloads, license keys, or subscription access without paying.
• Create fraudulent refunds or disputes leading to chargeback headaches.
• Mask broader compromises by using the vulnerability to inject legitimacy into fraudulent orders.

Likely exploitation workflow (high level, non-actionable)

1. Attacker discovers the webhook/notification URL. This can be inferred from plugin source, common endpoint naming, or by interacting with the site (e.g., adding a payment method).
2. The attacker crafts a POST (or GET, depending on implementation) to the handler including parameters that the plugin expects (order ID, status, amount).
3. Because the plugin does not verify a shared secret / signature / nonce, the plugin accepts the payload and updates the order status to paid/completed.
4. Digital goods are delivered automatically, or attacker triggers post-purchase actions (emails, downloads, license activation).
5. Reconciliation shows missing payments in the processor account but orders marked as paid in WooCommerce.

We intentionally avoid sharing exact exploit payloads or endpoint details; the important point is that generic notification handlers without authentication are dangerous and easily abused by remote attackers.

Business and operational impact

• Financial loss due to unpaid digital deliveries and chargebacks.
• Fraud rings may exploit the vulnerability to obtain goods at scale (automation + digital goods = profit).
• Reputation damage and customer trust erosion after a fraud incident.
• Increased workload: manual reconciliation, refunds, customer disputes, and audits.
• Potential for attackers to use the access vector as pivot to other site compromises (by combining with other vulnerabilities or social engineering).

Detection — Signs your site may have been targeted or abused

Audit your logs and WordPress records for the following:

• Sudden increase in orders marked “completed” where no matching transaction exists in your Payeer account.
• Orders completed from the same remote IPs that do not correspond to known payment provider IP ranges.
• Repeated POST requests to uncommon endpoints shortly before order status changes.
• Same user agent strings or automated-looking requests associated with “order paid” events.
• Orders where customer email or payment details are empty, anomalous, or otherwise suspicious.
• Unexpected changes to plugin files or new files in wp-content/uploads or plugin directories (could indicate post-exploitation persistence).

Check WooCommerce order notes (required for many gateways). Many plugins add order notes when receiving IPN/webhook notifications — these may contain raw request details you can use to investigate.

Immediate mitigations (short-term, do this now)

If you run a store using the affected plugin and cannot immediately remove the plugin or apply a vendor patch (none available yet), follow these steps to reduce risk:

1. Disable the plugin temporarily.
   This is the safest immediate action. It prevents further unauthenticated callbacks from being processed and stops attackers from exploiting the vulnerability.
2. If you cannot disable the plugin:
   Restrict access to the plugin’s notification endpoint using WAF or server rules (deny all, then allow only Payeer IP ranges — see below).
   Add a server-level rule that only allows POST requests with an expected secret header/value or blocks requests without a signature parameter.
3. Enforce strict reconciliation workflows:
   Stop any automated fulfillment for orders paid via this gateway. Switch to manual payment verification for new orders until the issue is resolved.
   Hold high-value orders for manual review.
4. Review recent orders:
   Reconcile each order marked as paid by this gateway against the Payeer merchant dashboard. Flag mismatches and suspend fulfillment for suspicious orders.
   Refund or cancel orders only after manual verification and following your dispute policy.
5. Xoay vòng bí mật:
   If the plugin used stored API credentials or secrets and you suspect compromise, rotate those credentials in your Payeer merchant account.
6. Theo dõi nhật ký:
   Enable detailed access and application logging for the next 30 days. Note patterns (IP, user-agent, frequency).

WP-Firewall immediate virtual-patching (WAF) guidance

WP-Firewall customers can reduce exposure immediately by enabling targeted virtual patches (WAF rules). The goal is to block unauthenticated attempts to trigger the plugin’s payment-handler endpoints and block suspicious payloads associated with order completion.

Below are sample ModSecurity-style rules and conceptual descriptions you can adapt to your environment. These are intentionally generic patterns and should be tested in staging before applying to production.

Ghi chú: Replace /wp-json/payeer/* and parameter names with the exact paths/keys observed on your site if known.

Example (conceptual) ModSecurity rules:

# Block POST requests that target the Payeer webhook without a valid X-PAYEER-SIGN header
SecRule REQUEST_METHOD "POST" "chain,phase:2,deny,status:403,id:1000010,msg:'Block unauthenticated Payeer webhook calls'"
  SecRule REQUEST_URI "@rx /(wp\-content/plugins/crypto-payeer|wc-api=payeer|/wp-json/payeer|/payeer/notify)" "t:none"
  SecRule REQUEST_HEADERS:X-PAYEER-SIGN "!@rx .+"

# Allow only trusted Payeer IPs to reach webhook; otherwise deny
SecRule REQUEST_URI "@rx /payeer/notify" "phase:1,pass,id:1000020,nolog,ctl:ruleRemoveById=1000010"
SecRule REMOTE_ADDR "!@ipMatch 1.2.3.0/24,2.3.4.0/24" "phase:1,deny,status:403,id:1000021,msg:'Block unknown IP to Payeer notify endpoint'"

# Deny attempts to set order status to completed via webhook-like endpoints without token
SecRule REQUEST_METHOD "POST" "phase:2,chain,id:1000030,msg:'Block unauthenticated order completion attempt'"
  SecRule ARGS_GET|ARGS_POST|REQUEST_BODY "@rx (status|order_status|pay_status)=(paid|completed|success)" "t:none"
  SecRule ARGS_GET|ARGS_POST|REQUEST_BODY "!@rx (secret|signature|hash|x-payeer-sign)" "t:none"
  SecRule REQUEST_URI "@rx payeer|payeer_notify|wc-api=payeer" "t:none"

# Simple rate limiting pseudo-rule (implement with your WAF's native rate limiting features)
# e.g., limit 10 requests per minute per IP to the webhook URL

How WP-Firewall helps:

• Virtual patching: WP-Firewall can deploy tuned WAF rules to intercept and block unauthenticated payment-completion requests without waiting for the plugin author to release a fix.
• Signature-based blocking: Detects patterns of abuse and stops automated jobbers from marking orders as paid.
• Behavioral rules: Rate-limit and challenge suspicious IPs and user agents targeting payment endpoints.
• File-integrity monitoring: Detects plugin file modifications or suspicious uploads that might follow exploitation.

If you do not run WP-Firewall yet, consider enabling managed firewall rules that immediately block unauthenticated access to suspected webhook endpoints and protect against suspicious patterns described above.

Practical server-level mitigations (Apache/Nginx)

If you cannot use WP-Firewall, you can apply server-level blocks:

Nginx snippet (deny access by default and allow only Payeer IPs):

location ~* /(wp-content/plugins/crypto-payeer|wc-api=payeer|/wp-json/payeer|/payeer/notify) {
    allow 1.2.3.0/24; # replace with Payeer IP ranges if provided by processor
    deny all;
}

Apache .htaccess snippet:

<If "%{REQUEST_URI} =~ m#(wp-content/plugins/crypto-payeer|wc-api=payeer|/wp-json/payeer|/payeer/notify)#">
    Require ip 1.2.3.0/24
    Require all denied
</If>

Alternatively, add a shared secret validation at server level using a custom middleware or script that checks for a pre-shared header.

Danh sách kiểm tra ứng phó sự cố (nếu bạn nghi ngờ có sự xâm phạm)

1. Cô lập:
   Disable the vulnerable plugin immediately (or take the site temporarily offline if significant compromise suspected).
2. Preserve logs:
   Collect access logs, PHP-FPM logs, and WooCommerce logs for the timeframe of suspected exploitation.
3. Reconcile:
   Compare all orders marked completed via the Payeer gateway with the Payeer merchant account. Flag mismatches.
4. Bao gồm:
   Revoke credentials related to the plugin/merchant integration and rotate API keys.
   Change webhook URLs or enable new secrets.
5. Khảo sát:
   Review suspicious orders for IP patterns, user-agent strings, or rapid automated sequences.
   Inspect plugin files for tampering or backdoors.
6. Remediate:
   Cancel or hold suspicious orders pending manual verification and further forensic analysis.
   Rebuild compromised files from clean backups when necessary.
7. Communicate:
   Notify affected customers if fraudulent access to their paid resources occurred.
   Work with payment processor support to investigate fraudulent transactions or disputes.
8. Learn & harden:
   Post-incident, implement WAF rules, stricter reconciliation procedures, and developer guidance to prevent recurrence.

Developer guidance — how to fix properly

If you are a plugin developer responsible for the affected code, the long-term fix should include the following:

1. Strict webhook validation:
   Implement message signing (HMAC) for all callbacks. Sign the payload with a merchant secret and require verification of that signature on every notification.
   Use time-limited nonces or timestamps to prevent replay attacks.
2. Validate payment details:
   Verify the order exists and that the amount and currency match the order.
   Only mark an order as paid after verifying the transaction status with the processor (ideally via a server-to-server API call, not only via incoming webhook).
3. Authenticate the source:
   If the provider uses IP ranges, use them as a secondary check (careful: IP ranges can change). Primary mechanism should be cryptographic signature.
   Enforce TLS mutual or token-based verification where supported.
4. Use proper WooCommerce APIs:
   Use WooCommerce-provided hooks and order API to update status; do not directly alter DB records.
   Add detailed order notes for each webhook processed for traceability.
5. Idempotency and replay protection:
   Ensure webhook handlers are idempotent: repeated notifications should not cause duplicate fulfillment.
   Store and check transaction IDs to prevent reprocessing.
6. Nguyên tắc đặc quyền tối thiểu:
   Avoid exposing unnecessary endpoints or actions that modify order state without authorization.
7. Secure coding practices:
   Sanitize and validate all inbound parameters.
   Avoid trusting client-controlled values such as order-level flags.
8. Testing:
   Unit and integration tests that simulate malicious and malformed requests.
   Security code review and use of automated SAST/DAST tools.

Detection rules and indicators for security teams

Monitor for:

• Requests containing typical payment-processor parameter names (order_id, amount, status) coming from unusual IPs or user agents.
• Quick status changes from “pending” to “completed” without corresponding payment transactions in the processor dashboard.
• High frequency of requests to the same endpoint with varying order IDs.
• Patterns such as multiple orders marked completed from the same IP or same user-agent in a short window.

Log searches sample queries (conceptual):

• Apache access logs: grep -E "payeer|payeer_notify|wc-api=payeer" access.log
• Search WooCommerce order notes for recent webhook entries: wp postmeta queries or use WooCommerce backend.
• SIEM correlation: rules to raise alert if orders marked completed via this gateway are more than X% without matching payment in external processor.

Long-term recommendations for store operators

• Prefer payment plugins that support signed webhooks or secure callback verification.
• Limit automated fulfillment for new/unknown gateways until production-tested.
• Implement multi-layer fraud detection: device fingerprinting, velocity checks, and manual reviews for high-value items.
• Keep WordPress core, themes, and plugins updated and subscribe to security intelligence sources.
• Enforce least privilege on admin accounts, use strong MFA, and enable role management for staff.

Những câu hỏi thường gặp

Q: My store doesn’t use the affected plugin. Do I need to worry?
A: If you don’t have the plugin installed or active, you are not directly impacted by this vulnerability. However, you should still ensure that any other payment integrations validate webhooks and signatures correctly — this class of vulnerability is common in payment gateway implementations.

Q: Can I just rely on the payment processor to catch fraudulent transactions?
A: No. Payment processors and merchant accounts may not block a plugin-side manipulation that marks an order as paid in your WooCommerce database. Always reconcile orders against processor transactions and rely on server-side signature verification for trust.

Q: If I disabled the plugin, will I still be billed by Payeer?
A: Disabling the plugin prevents the site from processing incoming callbacks; billing at the payment processor happens independently. Reconcile your Payeer merchant account separately from WooCommerce.

Why virtual patching/WAF matters now

When an official plugin update or vendor patch is not available, virtual patching provided by a WAF is the fastest way to reduce risk. Virtual patching intercepts malicious requests at the edge before they reach the vulnerable code path, effectively shielding the site while a permanent fix is developed and tested.

WP-Firewall virtual patches for this issue include:

• Blocking unauthenticated access to likely webhook endpoints.
• Requiring presence/format of signature tokens and blocking requests without them.
• Rate limiting to blunt automated exploitation attempts.
• Monitoring and alerting on suspicious patterns targeting the gateway.

These measures dramatically reduce the attack surface and buy time to deploy a thorough remediation.

New title to encourage sign-up: Protect Your Store Now — Start With Free Managed Firewall Protection

If you’re responsible for a WooCommerce store, now is not the time to hope you won’t be targeted. WP-Firewall’s Basic (Free) plan gives you essential, managed protection immediately — including a managed firewall, a WAF with OWASP Top 10 mitigations, an automated malware scanner, and unlimited bandwidth protection. These features are designed to stop unauthenticated attacks like payment-bypass attempts and provide proactive monitoring while you perform deeper incident response and remediation.

Sign up for the WP-Firewall Basic (Free) plan right away to get instant protection: https://my.wp-firewall.com/buy/wp-firewall-free-plan/

(If you want additional capabilities, the Standard and Pro plans add automatic malware removal, IP blacklisting/whitelisting, monthly security reports, auto virtual patching, and premium support options.)

Sample checklist for WP-Firewall users (actionable next steps)

1. If you have the affected plugin installed:
   Immediately disable it if possible OR apply WP-Firewall’s virtual patching profile for payment-gateway webhook protections.
2. Enable the WAF and ensure the ruleset that protects webhook endpoints is active.
3. Enable detailed logging and alerting for webhook endpoints.
4. Stop automated fulfillment for orders from this gateway until you can reconcile with the processor.
5. Reconcile recent orders and investigate anomalies.
6. Rotate integration secrets and webhook endpoints where supported.
7. Consider upgrading to a paid plan if you need automatic malware removal and managed virtual patching for ongoing protection.

Closing thoughts from WP-Firewall experts

Payment gateway integrations are a high-risk target because they interact with order fulfillment logic and often trigger automatic actions. A single missing signature or missing access control check can allow remote attackers to obtain goods and services for free, and can be used as an initial foothold for further abuse.

Security isn’t a single fix — it’s layered. WAFs and virtual patches buy you time and reduce immediate exposure, but they should be paired with secure development practices, proper webhook verification, and operational controls like manual reconciliation and order-hold policies for new or sensitive payment channels.

If you need help assessing exposure, deploying virtual patches tailored to this vulnerability, or incident response support, WP-Firewall’s team is available to assist. Ensure your store’s payment flows require cryptographic verification. If you use the “Crypto Payment Gateway with Payeer for WooCommerce” plugin (<= 1.0.3), treat this as an urgent issue and act now.

Appendix: Helpful resources and further reading

• CVE reference: CVE-2025-11890
• WooCommerce developer docs: webhook best practices and order management.
• General guidance: Verifying incoming webhooks and HMACs for payment providers.
• Security checklist: Payment gateway integration checklist for developers.

---

If you want, we can produce a tailored, site-specific set of WAF rules (tested for your server environment) and a forensic checklist to reconcile orders and triage suspicious activity on your store.