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The Pros and Cons of Cloud Armor (GCP WAF)


Why does Google's Cloud Armor not dominate the industry like Google's other products?


Cloud Armor Web Application Firewall (WAF) is a critical defense mechanism for web applications. Its primary function is to act as a barrier between web applications and the internet, scrutinizing and filtering HTTP traffic.


In 2023, the WAF market has seen explosive growth, reaching a staggering $5.48 billion. Yet, it's intriguing to note that WAF solutions offered by tech giants like Google (such as Google's Cloud Armor) have found themselves somewhat overshadowed by the prominence of competitors like Cloudflare.


What is Cloud Armor (GCP WAF)?

Google Cloud Armor is a web application firewall (WAF) service offered by Google Cloud Platform (GCP). It safeguards web applications from common vulnerabilities, such as SQL injection, cross-site scripting (XSS), and other malicious activities.


What sets Cloud Armor apart is its user-friendly features. Users have the flexibility to customize defense rules, spanning from IP-based access controls to geolocation-based access policies. Additionally, it supports rate limiting to effectively counter distributed denial of service (DDoS) attacks.


Can Cloud Armor Protect Against the Most Common Web Application Security Risks?

Google Cloud Armor can provide robust protection against common web application security risks.

1. Distributed Denial-of-Service (DDoS) Attacks

DDoS attacks overwhelm a website with an influx of traffic, rendering it inaccessible to legitimate users. Cloud Armor offers robust DDoS protection through a combination of: Global Anycast Network: Cloud Armor's network is geographically distributed, ensuring high availability and the ability to absorb large-scale attacks.

  • Adaptive Protection: Automatically detects and mitigates DDoS attacks based on traffic patterns, minimizing service disruptions.

  • Managed Protection: Provides comprehensive DDoS protection with dedicated security experts monitoring and managing your defenses.

2. OWASP Top Attacks

The OWASP Top 10 represents a consensus list of the most critical web application security risks. Cloud Armor addresses these vulnerabilities through:

  • Preconfigured WAF Rules: Offers pre-built rules to mitigate common OWASP Top 10 attacks such as SQL injection, cross-site scripting (XSS), and command injection.

  • Custom WAF Rules: You can create custom WAF rules to address specific vulnerabilities unique to your application.

  • Layer 7 Filtering: Inspects web traffic at the application layer, allowing it to detect and block malicious payloads associated with OWASP Top 10 attacks.

3. Zero-Day Attacks

Zero-day attacks exploit previously unknown vulnerabilities in software, making them difficult to defend. While Cloud Armor's preconfigured and custom WAF rules can offer some protection, they're not foolproof against zero-day attacks. But you can use specialized tools like open-appsec to tackle such situations.


Here's a comparison between Cloud Armor and open-appsec in terms of zero-day protection:

Pros of Using Cloud Armor

Continuing our exploration, let's focus on the advantages of using Google Cloud Armor.

1. Scalability

Cloud Armor's automatic scalability is a game-changer in handling large-scale DDoS attacks. Leveraging Google's robust global network, it can absorb and mitigate attacks, ensuring uninterrupted application performance even during peak traffic.


Implementation Tips:

  • Configure your security policies to scale up during attacks automatically.

  • Consider using Cloud Armor's Adaptive Protection feature for intelligent detection and mitigation of L7 DDoS attacks.


2. Integration with Google Cloud Services

Cloud Armor integrates seamlessly with other Google Cloud services, such as Cloud Load Balancing and Cloud Functions. This integration simplifies security architecture, eliminating the need for complex configurations.


Implementation Tips:

  • Use Cloud Load Balancing to distribute traffic across multiple instances, enhancing your application's resilience against attacks.

  • Use Cloud Functions for automated threat analysis and response workflows.


3. Managed Protection

Google Cloud Armor offers a managed protection service that handles security rule updates, threat analysis, and incident response. It removes the burden of managing complex security infrastructure and frees up your time and resources to focus on other core business functions.


Implementation Tips:

  • Consider managed protection only if your organization lacks dedicated security resources or requires a hands-off approach.


4. Support for Hybrid and Multi-Cloud Deployments

Cloud Armor supports applications and services hosted on-premises or in other clouds. This feature eliminates the need for separate security solutions for different environments, simplifying management and reducing costs.


Implementation Tips:

  • Use Cloud Armor's Cloud Interconnect service to connect your on-premises network to Google Cloud.

  • Implement Cloud Armor's security policies consistently across your entire environment.


5. Bot Management

Bots can significantly impact website performance and security. Cloud Armor provides built-in support for advanced bot detection features like reCAPTCHA and rate limiting to fortify your web applications.


Implementation Tips:

  • Redirect requests to reCAPTCHA Enterprise for assessment to distinguish between human users and automated clients.

  • Evaluate and apply configured actions based on the attributes of reCAPTCHA Enterprise tokens attached to incoming requests.

  • Use rate limiting rules to prevent token abuse through multiple uses per unique reCAPTCHA action-token, session-token, or exemption cookie.


6.   Access Control

Cloud Armor provides fine-grained access control to your applications and services. You can define who can access your resources and what actions they can perform, minimizing the potential for security incidents.


Implementation Tips:

  • Use Cloud Armor's Identity and Access Management (IAM) integration to control user access and reviews based on their roles and permissions.

  • Use Cloud Armor's logging and monitoring capabilities to track user activity and identify suspicious behavior.


Cons of Using Cloud Armor

While Cloud Armor offers robust security features, it's essential to be aware of potential drawbacks before adopting the solution. Understanding these cons will help you make an informed decision based on your organization's specific needs.

1. Pricing and Expensive Cost

One significant drawback of Cloud Armor is its pricing structure, which can be perceived as expensive compared to free or open-source alternatives like open-appsec.


Cloud Armor charges a per-second billing rate based on the amount of traffic it inspects. Although this model provides flexibility, it can incur significant costs for high-traffic websites and applications.


Mitigation Tips:

  • Carefully estimate your expected traffic volume.

  • Implement cost optimization strategies, such as using Cloud Armor's regional or global tiered pricing options.

  • Continuously monitor your usage patterns.


2. Complex for Beginners to Learn

Cloud Armor offers a wide range of features, and customization options may challenge beginners and create a potentially steep learning curve. New users might find it overwhelming due to limited documentation and insufficient training resources.


Mitigation Tips:

  • Consider Google Cloud's official documentation as a primary resource.

  • Explore tutorials and case studies available online.

  • Engage in hands-on practice.


3. Limited Support for Non-HTTP Protocols

Cloud Armor currently only supports HTTP and HTTPS traffic inspection. It cannot be used to protect applications and services that rely on other protocols, such as FTP or SMTP.


Mitigation Tips:

  • If your applications require protection for non-HTTP protocols, consider using a different WAF solution alongside Cloud Armor.

4. Occasional Lag in Performance

While Cloud Armor provides robust security features, users have reported latency instances during high-traffic periods or under certain conditions. This delay can affect the overall user experience and application responsiveness.


Mitigation Tips:

  • Implement thorough performance monitoring.

  • Conduct load testing to simulate high-traffic scenarios.

  • Evaluate alternative solutions like open-appsec.


5. Signature-Based Detection

Cloud Armor primarily relies on pre-defined signatures to detect and block malicious attacks. Although this approach is effective against known threats, there can be some shortcomings in rapidly adapting to new and evolving attack vectors.


Mitigation Tips:

  • Use Cloud Armor Adaptive Protection, which uses ML to detect and mitigate emerging threats.

  • Combine Cloud Armor with other security solutions that offer behavior-based or anomaly-detection capabilities.

  • Use open-appsec, which is not signature-dependent.


Secure Your Apps with open-appsec

While Google Cloud Armor offers impressive features, its significant drawbacks could prevent organizations from adopting it, potentially contributing to its lower usage than alternative tools.


Tools like open-appsec address these limitations, emerging as a straightforward choice for a comprehensive WAF solution. Fueled by machine learning, open-appsec excels in pre-emptive threat protection against OWASP Top-10 and zero-day attacks, eliminating the need for constant updates. open-appsec's innovative solution ensures secure HTTPS traffic inspection, enabling the safe storage of SSL certificates in public cloud secrets storage, and also Rate Limiting/DDoS protection feature. It can be deployed in all typical environments, Linux, Docker, Kubernetes in the Cloud as well as on premise.


open-appsec is an open-source project that builds on machine learning to provide pre-emptive web app & API threat protection against OWASP-Top-10 and zero-day attacks. It simplifies maintenance as there is no threat signature upkeep and exception handling, like common in many WAF solutions.

Reserve a demo today to learn more about how open-appsec works. You can also experiment with deployment in the free Playground.


Experiment with open-appsec for Linux, Kubernetes or Kong using a free virtual lab

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