插件名稱	Event Tickets
Type of Vulnerability	Unauthenticated Payment Bypass
CVE Number	CVE-2025-11517
Urgency	High
CVE Publish Date	2025-10-18
Source URL	CVE-2025-11517

Urgent Notice: Event Tickets (≤ 5.26.5) Plugin Vulnerability – Unauthenticated Payment Bypass (CVE-2025-11517) – Essential Actions for WordPress Site Owners

Insights and guidance from Managed-WP’s US-based security experts on the CVE-2025-11517 vulnerability impacting the Event Tickets plugin, including threat overview, detection strategies, mitigation, monitoring, and response best practices.

作者： Managed-WP Security Team
Date: 2025-10-18

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Overview: A critical authentication bypass vulnerability impacting Event Tickets versions ≤ 5.26.5 was publicly disclosed and assigned CVE-2025-11517. This flaw enables unauthenticated attackers to bypass payment verification, effectively acquiring paid tickets without completing transactions. This advisory outlines the threat impact, essential immediate steps, detection methods, interim protective measures if patching cannot be done immediately, long-term hardening techniques, and how Managed-WP’s services can shield your site now.

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Fast Facts

• Affected Plugin: Event Tickets (WordPress) – versions ≤ 5.26.5
• CVE ID: CVE-2025-11517
• Severity: High (CVSS ~7.5)
• Vulnerability Type: Authentication Bypass / Unauthenticated Payment Bypass
• Remedy: Version 5.26.6 or newer – update immediately
• Attack Complexity: Low to Moderate – requires no authentication
• Potential Impact: Fraudulent ticket completion, financial loss, and further system compromise depending on setup

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Why This Vulnerability Is a Major Concern

Plugins handling ticket sales are lucrative targets because they control transactional data, payments, and access permissions. This flaw permits unauthorized users to mark tickets as paid or bypass payment completely, enabling free entry into paid events. Resulting losses are not only financial; trustworthiness and reputation can be severely damaged. Additionally, attackers may manipulate data to trigger downstream processes like email notifications or access credentials, increasing risk.

Given the vulnerability does not require authentication, the attack vector is wide open, with automated exploit attempts expected at scale.

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Technical Breakdown

This vulnerability falls into the category of broken authentication and payment bypass. Vulnerable plugin versions allow unauthenticated HTTP requests to modify ticket/order statuses or invoke payment handlers that circumvent necessary gateway checks.

• Attackers can receive fully paid tickets without actual payment.
• Order metadata and related attendee records may be tampered with.
• No WordPress login is required to exploit this flaw.
• The root cause is improper validation and authorization in key endpoints handling payment status updates.

The plugin vendor addressed this issue in version 5.26.6. Sites running prior versions remain at high risk.

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Immediate Recommended Actions

1. Verify Your Plugin Version
   • Access WordPress Admin → Plugins → Installed Plugins → Event Tickets.
   • If the version is 5.26.5 or older, proceed quickly with the following steps.
2. Update the Plugin
   • Upgrade Event Tickets to version 5.26.6 or above immediately.
   • Clear caches including object, page, and CDN caches post-update.
   • Test purchase workflows on staging or test environments to ensure proper functionality.
3. Temporary Measures if Immediate Update Is Not Possible
   • Place ticket purchasing pages into maintenance mode where feasible.
   • Disable or pause public ticket sales temporarily.
   • Enable firewall rules or WAF to block suspicious endpoints.
   • Intensively monitor logs for suspect activity.
4. Audit Ticket Orders and Attendee Data
   • Check for orders marked “paid” without corresponding gateway transactions.
   • Investigate any unusual bulk or suspicious activity in orders.
5. Credentials Rotation
   • Reset admin passwords and rotate API keys for payment gateways if compromise is suspected.
   • Ensure hosting and control panel credentials are secure.
6. Conduct Full Malware and Integrity Scan
   • Scan for modified plugin or core files and indicators of compromise.
   • Engage professional incident response if persistence is detected.

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Temporary Technical Controls for Risk Mitigation

Until you can apply the official patch, apply the following mitigations to reduce attack surface. These are not replacements for patching.

1. Suspend Public Event Checkout
   • Temporarily close event registrations or require manual approval.
   • Display notification pages indicating a temporary hold on ticket purchases.
2. Block Vulnerable REST and AJAX Endpoints
   • Use your Web Application Firewall (WAF) or server config to reject unauthenticated POST requests targeting the plugin’s REST or AJAX routes affecting payment.
   • If using Managed-WP’s WAF services, activate rules designed to block these unauthorized API calls.
3. Implement Rate Limiting and IP Filtering
   • Throttle ticketing-related endpoints to curb automated mass exploitation attempts.
   • Temporarily block or monitor traffic from suspicious locations or IPs.
4. Enforce Login for Purchases (If Business Logic Allows)
   • Require customers to create and authenticate accounts before checkout.
5. Monitor Payment Gateway Transaction Consistency
   • Regularly cross-check order data with payment gateway logs to flag payment discrepancies.
6. Add Server-Side Request Verification Headers
   • Configure server or reverse proxy to verify requests to sensitive endpoints carry a pre-shared verification header.

Warning: Testing these temporary controls in a staging environment before applying to production is highly recommended to avoid service disruptions.

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Detecting Signs of Exploitation

Actively review the following indicators to detect possible exploitation:

1. Order Irregularities
   • Orders marked “paid” or “completed” without matching payment provider transaction records.
   • Attendee records with fake or missing buyer contact info.
   • Unusually low or zero payment amounts showing as paid.
2. Web Server Logs
   • POST requests to REST or admin-ajax.php endpoints with parameters such as “mark_paid” or “set_status.”
   • High volume or repetitive requests from the same IPs or with suspicious user agents.
3. Plugin and WordPress Logs
   • Payment completion entries lacking corresponding gateway callbacks.
   • Sudden spikes in errors, warnings, or failed verifications.
4. Payment Gateway Records
   • Mismatch between gateway transaction logs and plugin order statuses.
5. Hosting and Security Logs
   • Unauthorized file changes, unexpected admin logins, or new admin accounts creation.
   • Suspicious scheduled or background processes.

If evidence of fraudulent orders is found, suspend affected events and notify customers promptly. Engage in payment processor dispute resolution if warranted.

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Incident Response: Immediate Steps if Exploited

1. 遏制
   • Disable ticket purchasing functionality immediately.
   • Block suspicious IP addresses.
   • Consider isolating the site to prevent further access by attackers.
2. Evidence Preservation
   • Capture forensic snapshots of server and WordPress logs, databases.
   • Avoid overwriting logs required for investigation.
3. Eradication
   • Update plugin to 5.26.6 or later.
   • Remove any unauthorized or suspicious files.
   • Revert unauthorized order updates if possible; maintain detailed records.
4. Recovery
   • Restore backups if necessary.
   • Rotate all privileged user passwords and API tokens.
5. 通知
   • Inform affected customers and regulatory bodies as appropriate.
6. Review & Hardening
   • Implement recommended long-term security measures.
   • Conduct post-incident review and improve monitoring systems.

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Long-Term Security Enhancements

1. Keep WordPress Core and Plugins Current
   • Frequent updates reduce exposure windows for known vulnerabilities.
2. Strengthen Plugin Update Processes
   • Use staging environments and automated tests to avoid breaking live sites.
   • Consider safe auto-update configurations for critical security updates.
3. Implement a Managed Web Application Firewall (WAF)
   • Provides virtual patching and blocks exploits before patch roll-out.
4. Enforce Principle of Least Privilege
   • Limit admin accounts and enforce two-factor authentication (2FA) for privileged users.
5. Centralize Logging and Alerts
   • Monitor payment and order anomalies with actionable alerts.
6. Conduct Regular Security Testing
   • Security audits and a responsible disclosure program minimize future risks.
7. Isolate Payment Workflows
   • Rely on gateway callbacks with cryptographic verification; reduce sensitive logic in plugin code.

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Advantages of Using Managed-WP’s Firewall for This Vulnerability

Operators using Managed-WP’s managed firewall benefit from:

• Immediate deployment of updated rule sets that virtually patch the vulnerability across customers globally.
• Blocking of unauthenticated requests attempting to modify order/payment status.
• Rate limiting and detection of suspicious patterns to slow exploitation velocity.
• Alerting and logging to surface unusual activity for early investigation.

Our team translates vulnerability disclosures into actionable defense signatures rapidly, giving your site protection before plugin updates can be applied.

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Safe Update Procedure

1. Backup Everything
   • Complete offsite backup of files and databases.
2. 啟用維護模式
   • Prevent live attacks during update process.
3. Update on Staging
   • Verify critical checkout and payment flows work as expected.
4. Update Production Plugin
   • Apply the update, clear caches, and test key workflows immediately.
5. Validate Order and Payment Records
   • Confirm transaction integrity between your site and payment gateway logs.
6. Reopen Ticket Sales and Monitor

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Detection Checklist for Your Security Team

• Is Event Tickets plugin at version 5.26.5 or earlier?
• Has update to version 5.26.6+ been applied?
• Are there unauthorized orders marked paid?
• Have IPs been detected issuing repeated POST requests on ticketing endpoints?
• Any unusual spike in ticket purchases or registrations?
• Do logs show suspicious POST requests to REST/AJAX endpoints with payment status parameters?
• Have admin credentials been used from unexpected locations?
• Have payment API keys been rotated after suspected compromise?

If any answers are affirmative, initiate containment and full incident response immediately.

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Conceptual ModSecurity-Style WAF Rule Suggestions

The below provides a defensive framework to help WAF administrators create rules. Implement and test carefully.

• Deny unauthenticated POST requests to REST API endpoints within the plugin’s namespace.
• Block requests attempting to set order statuses to “paid” or “completed” without valid payment transaction IDs.
• Throttle excessive ticket creation or status update attempts per IP per timeframe.

Note: Managed-WP customers should request and enable targeted rule sets for this vulnerability to ensure proactive protection.

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Customer Communications Guidance if Records Are Affected

• Be transparent, informing customers of the detected unauthorized ticket issuance and ongoing investigation.
• Provide clear instructions for ticket verification or replacement workflows.
• Offer remediation such as refunds or replacements when appropriate.
• Maintain open communication channels for updates and support inquiries.

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Root Causes Behind Recurring Payment Bypass Vulnerabilities

Ticketing and ecommerce plugins have intricate transaction flows often involving client-side validation, webhooks, and gateway callbacks. Common issues leading to flaws include:

• Missing robust server-side authorization on endpoints that modify financial states.
• Over-trust in client-supplied data without cross-verification from payment gateways.
• Reliance on frontend nonces or JavaScript checks that attackers can bypass through direct HTTP requests.

Strong server-side validation and minimal trust on external inputs are non-negotiable for payment flow security.

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How Managed-WP Supports Your Security Posture

As a trusted WordPress security partner, Managed-WP offers:

• Continuously updated, managed WAF rule sets including virtual patches for critical vulnerabilities.
• Rapid deployment of protective signatures immediately after vulnerability disclosures.
• Enhanced malware scanning and incident remediation support.
• Tiered services allowing customization from basic protection to full incident management.

Existing Managed-WP clients are encouraged to enable auto-updates on firewall rules for seamless protection delivery.

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Get Started with Managed-WP Free Protection Today

Protect Your WordPress Site Against Known Threats

For immediate baseline security while planning further updates and investigations, sign up for Managed-WP’s free Basic plan. This includes managed firewall protections, malware scanning, and defenses against the OWASP Top 10 risks — a solid foundation against vulnerabilities of this kind. Start your free protection now: https://my.wp-firewall.com/buy/wp-firewall-free-plan/

For advanced remediation, virtual patching, and expert support, consider our Standard or Pro plans.

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常問問題

Q: Is simply updating to 5.26.6 enough to secure my site?
A: Updating is essential, but if exploitation occurred, additional incident response steps are required to remediate unauthorized changes and ensure no persistence remains.

Q: Can I rely solely on a WAF for protection?
A: A WAF is critical for immediate defense and can block exploits rapidly, but it must be complemented by timely patching for comprehensive security.

Q: Should I refund affected customers?
A: That depends on your business policies and extent of fraud. Transparency and clear communication with your customers are paramount.

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Final Recommendations from Managed-WP Security Experts

This vulnerability highlights key lessons:

1. Any plugin managing payments must enforce strict server-side validation — never trust only client-side checks.
2. Fast action combining managed firewall protection with immediate patching is vital to minimize damage.

If you manage WordPress sites with ticketing or ecommerce functionality, address this advisory as high priority: update Event Tickets to 5.26.6 or greater, audit recent transactions, and apply recommended mitigations if you cannot patch immediately.

For expert assistance in assessing exposure, applying virtual patches, or incident investigation, Managed-WP’s team is ready to help. Sign up for our free plan to gain immediate baseline protection: https://my.wp-firewall.com/buy/wp-firewall-free-plan/

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Appendix: Useful Resources

• CVE-2025-11517 Public Record – review official vulnerability details.
• Event Tickets Plugin Release Notes – consult the vendor’s updates and security advisories.
• Payment Gateway Reconciliation Guides – verify your transactions consistent with gateway data.

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作者： Managed-WP Security Team
For incident reviews or assistance, contact your Managed-WP portal or hosting provider’s incident support team.