How CDNs Report on Security Events Like Blocked Attacks or WAF Triggers

 Modern Content Delivery Networks (CDNs) are not only responsible for accelerating content delivery—they also serve as frontline security defenses for websites, applications, and APIs. CDNs often include integrated Web Application Firewalls (WAFs), DDoS mitigation systems, bot management, and threat intelligence. To ensure that these security features are actionable, CDNs provide robust reporting and monitoring on security events such as blocked attacks, malicious traffic, and WAF triggers.

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1. Types of Security Events Monitored by CDNs

CDNs generate reports for a wide variety of security-related activities at the edge:

• WAF Triggers: When a request matches a WAF rule—for example, SQL injection, cross-site scripting (XSS), or command injection—the CDN logs the event and can block the request.

• DDoS Mitigation Events: Large-scale traffic floods intended to overwhelm origin servers are identified, absorbed, or filtered by the CDN.

• Bot Detection and Management: Automated bot traffic, credential stuffing attempts, or scraping activity can be flagged or blocked.

• Origin Shielding Events: Suspicious requests intended to probe the origin server are intercepted at the edge.

• TLS/SSL Violations: Unsuccessful or malformed SSL handshake attempts are recorded.

• Geo-Blocking or Access Control Events: Requests from disallowed regions or IP addresses are logged and blocked.

These events form a comprehensive view of the security posture at the network edge.

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2. Methods of Reporting Security Events

CDNs report security events through several mechanisms, allowing security teams to analyze, respond, and take preventive actions:

a. Dashboards and Analytics

Most CDN providers offer real-time dashboards that display security event metrics such as:

• Number of blocked requests

• WAF rule triggers and categories (SQLi, XSS, etc.)

• Top offending IP addresses or countries

• Attack patterns over time (hourly, daily, or weekly)

• DDoS attack duration, traffic volume, and mitigation actions

Dashboards allow security teams to visually track trends and spot anomalies without parsing raw logs.

b. Log Delivery

For deeper analysis, CDNs deliver raw security event logs through:

• Syslog or log streaming to SIEM (Security Information and Event Management) systems like Splunk, QRadar, or ELK Stack

• Batch log uploads to cloud storage (AWS S3, Azure Blob, GCP Storage) for archival and forensic analysis

• Webhook notifications for real-time alerting when specific rules are triggered

Logs typically include detailed information such as timestamp, client IP, requested URL, WAF rule triggered, action taken (block/allow), and associated headers.

c. Alerts and Notifications

CDNs can send automated alerts via:

• Email or SMS

• Webhooks to security orchestration platforms (SOAR)

• Integration with incident management tools like PagerDuty or OpsGenie

This ensures security teams receive immediate notifications for critical attacks or spikes in malicious activity.

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3. Correlation and Analysis

Integrating CDN security reports with other monitoring and SIEM tools enables:

• Correlation with backend logs: Understanding if an attack reached the origin or was fully mitigated at the edge.

• Trend analysis: Identifying frequent attack types, targeted endpoints, and vulnerable geographies.

• Proactive rule updates: Adjusting WAF rules or bot management policies based on historical attack patterns.

For instance, if repeated credential stuffing attempts originate from a particular region, policies can be updated to throttle or block traffic from that area.

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4. Real-Time and Historical Reporting

CDNs provide both real-time monitoring and historical reporting:

• Real-Time: Security dashboards show active attacks, WAF rule triggers, and ongoing mitigation actions. This allows teams to respond immediately to incidents.

• Historical: Aggregated logs over days, weeks, or months help in forensic investigations, compliance reporting, and identifying recurring attack vectors.

This dual approach ensures that security insights are both operational and strategic.

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5. Integration With Compliance and Security Frameworks

CDNs often structure security reporting to support regulatory compliance (GDPR, PCI DSS, HIPAA) by:

• Storing event logs securely with retention policies

• Masking sensitive user data in reports

• Providing audit trails of blocked attacks and WAF triggers

• Offering metrics on the effectiveness of security measures

This enables organizations to demonstrate regulatory compliance while maintaining robust edge security.

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6. Advanced Reporting Features

Some CDNs offer advanced security reporting capabilities, including:

• Geospatial attack maps showing regions generating malicious traffic

• Threat intelligence integration to correlate attacks with known malicious IPs or bot networks

• Attack severity scoring to prioritize response efforts

• Custom reporting and dashboards tailored to business-critical endpoints

These features help teams not only respond to attacks but also plan long-term defensive strategies.

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7. Example Scenario

Imagine a global e-commerce website protected by a CDN:

• During a flash sale, the WAF detects multiple SQL injection attempts targeting the checkout page.

• The CDN blocks these requests at the edge, preventing them from reaching the origin server.

• Real-time dashboards show the number of blocked attacks, originating IPs, and the specific WAF rules triggered.

• Logs are automatically forwarded to the company’s SIEM system for further correlation with server logs.

• Alerts notify the security team immediately, allowing them to review and adjust policies if necessary.

By using CDN security reporting, the website remains operational and secure while gaining insights into attack trends.

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8. Takeaway

CDNs play a critical role in monitoring, reporting, and mitigating security events at the network edge. By integrating dashboards, logs, alerts, and analytics, CDNs provide actionable intelligence on blocked attacks, WAF triggers, and anomalous traffic. This not only protects origin servers and applications but also equips security teams with the data needed to analyze trends, improve policies, and maintain compliance.

In today’s environment of increasing cyber threats, the visibility and reporting capabilities of CDNs are essential for maintaining robust, proactive web and application security.