Signal Sciences Cloud WAF

The Signal Sciences Cloud WAF (Cloud WAF) is an application security monitoring system that monitors for suspicious and anomalous web traffic and protects against attacks directed at the applications and origin servers that you specify.

Cloud WAF

Cloud WAF analyzes inbound traffic to your applications and origin servers to detect and identify threats and attacks. When enough attacks are seen from an IP address, Cloud WAF determines whether to allow the request, block the request, tag the request with signals, flag the IP address, or rate limit the IP address. You can choose to enable or disable the blocking feature.

Enabling Cloud WAF doesn’t require modifications to your applications or origin servers. In order to use Cloud WAF, you must upload a TLS certificate, add an origin server using the Signal Sciences Hosted Dashboard, and update your DNS records to point to the appropriate servers.

Threat Intelligence

As part of Cloud WAF, we may aggregate the attack data collected from Cloud WAF and combine it with data collected from security and other services offered as part of the Fastly platform, including for other subscribers. We use these data insights (Threat Intelligence) to analyze and detect potential future anomalies or attacks and to improve, secure, provide, and market Fastly services in a manner that does not associate the Threat Intelligence with or identify any subscriber. For example, you receive the benefits of this Threat Intelligence via the Network Learning Exchange (NLX) feature that adds a unique signal to information in the Hosted Dashboard and NLX alerts you to potential bad actors that have been identified elsewhere in the subscriber network.

Signal Sciences Cloud DDoS

Signal Sciences Cloud DDoS (Cloud DDoS) is an always-on service integrated in the Cloud WAF infrastructure that examines inbound traffic to detect and mitigate DDoS attacks before they reach the applications and origin servers that you specify. Cloud DDoS uses automated mitigation techniques to stop common network protocol-based floods including SYN floods and reflection attacks using UDP, DNS, NTP, and SSDP. Cloud DDoS requires no additional installation or maintenance.

Signal Sciences Hosted Dashboard

The Signal Sciences Hosted Dashboard (Hosted Dashboard) is a web interface that you can use to investigate anomalous web traffic and see what actions, if any, Cloud WAF performed in response to certain requests. You can also use the Hosted Dashboard to create Workspaces. A Workspace is a user-defined set of rules and settings for applications and origin servers. The Hosted Dashboard allows you to create multiple Workspaces to differentiate between one or more APIs, microservices, or web applications. For each Workspace, you can use the Hosted Dashboard to add rules for requests, configure site alert thresholds, and add integrations to other systems.


The Signal Sciences Application Programming Interface (API) allows you to integrate your applications and services with the Cloud WAF. It uses standard HTTP response codes and verbs to allow you to programmatically control all the same features that are available through the Hosted Dashboard. The Signal Sciences API provides a variety of endpoints that we document in our API reference documentation.

Control over data sharing

Cloud WAF gives you control over data shared with Fastly. The Hosted Services component of Cloud WAF does not create copies of or store your data as it passes through. The security components of Cloud WAF do not require transmission or collection of any sensitive or personally identifiable information to function other than IP addresses that are identified as the initiator of anomalous or suspicious requests and related metadata. The hosted agents and modules are designed to automatically redact other sensitive or personally identifiable information in fields that are known to commonly contain sensitive or personally identifiable information before transmission to Fastly. Also, the hosted agents and modules allow you to manually configure them via the Hosted Dashboard to redact any sensitive information or other information not needed to be transmitted to Fastly, other than the limited data required for the functionality of the security components of Cloud WAF. Together, the full data stream going through Cloud WAF is not copied or retained by Fastly, and, if properly configured, the portion of that data stream that is evaluated by the security components of Cloud WAF and shared with Fastly will not include your sensitive information other than the IP addresses identified as the initiator of anomalous or suspicious requests.

Feature availability

Feature availability depends on the platform you have purchased.

Feature Essential Professional Premier
Default attack signals Included Included Included
Default anomaly signals Included Included Included
Default dashboards Included Included Included
Custom Signals Not Included Included Included
Standard API & ATO signals Not Included Included Included
Advanced Rate Limiting Not Included Not Included Included
Edge Rate Limiting Not Included Not Included Included but requires active full-site delivery account


We provide documentation for the Cloud WAF in the Signal Sciences Help Center.


We bill you as specified in your applicable ordering document, according to the number of Workspaces, the average requests per second (RPS) processed by the Cloud WAF, and the overall traffic flowing through the Hosted Services in terabytes (TBs). We measure months according to Coordinated Universal Time (UTC).

Subscriber responsibilities

As a Subscriber, you can identify and maintain up to five points of contact for support communications. All support requests must be initiated from and communicated through the designated points of contact.


All WAF products that exist today, including the Cloud WAF, have several limitations:

  • False positives. Any WAF can mistake good traffic for bad. We strongly recommend you monitor your traffic via the Hosted Dashboard for a minimum of two weeks before blocking traffic. You don't want to start blocking traffic with configurations that are generating false positives.
  • Custom application vulnerabilities. If attackers discover a vulnerability unique to your application or the technologies you use, and if your WAF configuration does not have a rule to protect against exploits for that particular vulnerability, it will not be able to protect your application in that instance.
  • Inspection of HTTP and HTTPS traffic only. A WAF only inspects HTTP or HTTPS requests (layer 7). It will not process any TCP, UDP, or ICMP requests.
  • Security products note. No security product, such as a WAF or DDoS mitigation product, including those security services offered by Fastly, will detect or prevent all possible attacks or threats. Subscribers should maintain appropriate security controls on all web applications and origins, and the use of Fastly's security products do not relieve subscribers of this obligation. Subscribers should test and validate the effectiveness of Fastly's security services to the extent possible prior to deploying these services in production, and continuously monitor their performance and adjust these services as appropriate to address changes in the Subscriber's web applications, origin services, and configurations of the other aspects of the Subscriber's Fastly services.
This article describes a product that may use third-party cloud infrastructure to process or store content or requests for content. For more information, see the section on cloud infrastructure, data center, and physical security.
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