# What Are Cloud DDoS Attacks? Protecting Cloud Infrastructure Against DDoS

**URL:** https://securesys.com.tr/en/learning/ddos-simulation/what-are-cloud-ddos-attacks

![What Are Cloud DDoS Attacks? Protecting Cloud Infrastructure Against DDoS](/images/bilgi-merkezi/covers/cover-ddos-08.webp)

Moving to cloud infrastructure gives many organisations advantages in scalability, flexibility and high availability.

But using the cloud does not remove DDoS risk.

In some cases it simply changes the shape of the risk.

In a physical data centre environment an attack can target;

the internet link,

the firewall,

the router,

the load balancer.

In a cloud environment the attacker can target different components such as;

public IPs,

the cloud load balancer,

the API gateway,

the web application,

the authentication service,

the container platform,

the autoscaling mechanism.

**Cloud DDoS protection** therefore consists of more than using a high-capacity cloud provider.

The real question is this:

#### Can your cloud infrastructure stay both available and financially sustainable under attack?

At this point concepts such as **cloud DDoS, AWS DDoS protection, Azure DDoS protection, Google Cloud DDoS security, WAF, CDN, autoscaling, multi-region architecture and EDoS** become important.

#### What Is Cloud DDoS?

**Cloud DDoS** refers to distributed denial of service attacks targeting services running in the cloud.

Those targets may be;

- a virtual machine,
- a public IP,
- the cloud load balancer,
- the API gateway,
- a Kubernetes ingress,
- a web application,
- DNS,
- the authentication service,
- a serverless function.

Any of them can be hit.

The scalability of a cloud environment can reduce the attack's impact.

But it does not mean unlimited capacity.

And even if the attack does not technically bring the system down, it can raise costs significantly.

### Are Cloud Environments Safer Against DDoS?

In some respects yes.

Large cloud providers can offer advantages such as;

wide network capacity,

anycast infrastructure,

a global edge network,

automated mitigation.

But that does not mean every cloud workload is automatically secure.

A misconfigured public IP can be directly exposed to the internet.

An API endpoint can be serving without any rate limit.

An autoscaling group can keep opening new instances under attack.

The core principle of cloud security is therefore the same as ever:

**Trust the right architecture, not the default capacity.**

### What Is the Public IP DDoS Risk?

Public IP addresses in a cloud environment are a direct attack surface.

If a public IP sits on;

a virtual machine,

a load balancer,

a VPN gateway,

a public API,

the attacker can target that service.

In cloud architecture, therefore, direct internet exposure should be reduced as far as possible and traffic passed through controlled layers such as;

the CDN,

the WAF,

a reverse proxy,

the load balancer.

### Why Is Origin Exposure Critical in the Cloud?

A web application may sit behind a CDN and a WAF.

But if the attacker knows the backend origin IP, they can attack that address directly.

CDN and WAF protection are then bypassed.

In cloud environments, therefore;

security groups,

network ACLs,

firewall rules

must be used to restrict the origin to accepting traffic only from trusted edge sources.

### How Resilient Is a Cloud Load Balancer Against DDoS?

Cloud load balancers generally provide high scalability.

But they are not unlimited.

The loads for;

TLS handshakes,

new connection rate,

HTTP request rate,

backend connections

matter in particular.

And while the load balancer stays up, the application instances or database behind it can hit a bottleneck.

Looking at load balancer capacity alone is therefore not enough.

### Does Autoscaling Provide DDoS Protection?

Autoscaling brings new compute instances online as traffic rises.

That helps availability.

But if the attacker sustains the traffic, the system can keep growing.

Two outcomes can then follow:

**The service stays up.**

But at the same time:

**The cloud bill rises rapidly.**

Autoscaling is therefore not DDoS protection on its own.

Whether the traffic is legitimate must also be analysed.

### What Is EDoS?

**Economic denial of sustainability (EDoS)** describes an attack, particularly in cloud environments, that makes the service economically unsustainable rather than bringing it down entirely.

For example;

serverless functions are triggered continuously,

autoscaling opens hundreds of instances,

database I/O consumption rises,

egress traffic increases.

The system continues running.

But costs can climb to dozens of times normal.

In cloud DDoS security, therefore, **cost monitoring and budget protection** matter as much as technical security.

### Serverless DDoS Risk

Serverless architectures scale automatically.

That is a major advantage.

But when an attacker sends large numbers of requests, the function invocation count can rise rapidly.

This can create;

execution cost,

downstream database load,

API call cost.

In serverless applications, therefore;

rate limiting,

authentication,

quotas,

API gateway protection

are critical.

### How Is an API Gateway Protected Against DDoS?

The API gateway is one of the important defensive layers in cloud environments.

These controls can be applied:

#### Rate Limiting

A request limit per client.

#### Quota

A total usage limit within a given period.

#### Authentication

Reducing anonymous access.

#### Request Validation

Rejecting invalid or abnormal requests.

#### WAF Integration

Analysing HTTP attacks.

These controls can reduce API DDoS risk.

### What Does a Cloud WAF Do?

A cloud WAF analyses HTTP/HTTPS traffic at the application layer.

It can detect;

HTTP floods,

bot traffic,

API abuse,

malicious requests.

The advantage of cloud WAFs is that they are usually integrated into the edge network.

Traffic can therefore be filtered before reaching the origin.

### How Does a Cloud CDN Help with DDoS Protection?

A CDN;

serves static content at the edge,

reduces origin load,

spreads traffic geographically.

This improves the DDoS resilience of web-based services in particular.

But dynamic API traffic or authentication operations still reach the backend.

A CDN is therefore not enough on its own.

### What Is Multi-Region Architecture?

**Multi-region architecture** means the application running across more than one cloud region.

The aim is that when one region has a problem, the others continue serving.

Its DDoS advantage is that traffic load is distributed and a failover option exists.

But multi-region architecture involves complex topics such as;

data replication,

routing,

DNS,

application consistency.

### Active-Active Cloud Architecture

In an active-active structure, several regions can take traffic at the same time.

This can be strong for DDoS resilience.

Because the attack load does not fall on a single region.

But global load balancing and backend capacity must be designed correctly.

### Active-Passive Cloud Architecture

In the active-passive model the main region runs actively.

The second region sits on standby.

Failover can be performed during an attack or service outage.

The critical question in this model:

#### How quickly does failover happen?

RTO is the important metric here.

### Why Does Global Load Balancing Matter for DDoS?

A global load balancer can direct users to different regions or edge points.

This provides;

geographic distribution,

failover,

traffic steering.

If a particular region becomes overloaded during a DDoS attack, traffic can be spread to other regions.

But if the attack is global, it may not be enough on its own.

### How Is Anycast Used in Cloud DDoS?

Anycast allows the same IP address to be announced from different locations.

Traffic can therefore reach the nearest or most suitable edge point.

During a DDoS attack the traffic spreads across the wide infrastructure.

This approach is common in cloud and CDN-based DDoS solutions.

### Cloud DNS DDoS Protection

The DNS service is critical for the availability of cloud applications.

If DNS fails, users cannot reach the application even though it is up.

For that reason;

anycast DNS,

multiple DNS servers,

secondary DNS,

DNS rate limiting

can be used.

### The Risk Between Managed DNS and Self-Hosted DNS

Self-hosted DNS gives full control.

But capacity and DDoS defence are the organisation's responsibility.

Managed DNS services generally have larger distributed infrastructure.

For critical applications, choosing managed or redundant DNS can be advantageous for availability.

### Kubernetes DDoS Risk

In Kubernetes environments, applications can pass through the layers of;

the ingress controller,

the load balancer,

the service,

the pod.

A DDoS attack can affect different points in this chain.

Ingress controller CPU consumption can become critical, for instance.

Pod autoscaling can engage.

But the database may not scale at the same speed.

Kubernetes DDoS resilience must therefore be tested end to end.

### Does Kubernetes HPA Solve DDoS?

The **horizontal pod autoscaler (HPA)** can increase the pod count as load rises.

That helps availability.

But if the attack traffic continues, the pod count can keep growing.

Node capacity or backend services can also form a limit.

HPA is therefore not DDoS mitigation on its own.

### Can the Ingress Controller Be a DDoS Bottleneck?

Yes.

An ingress controller can perform operations such as;

TLS termination,

routing,

rate limiting,

WAF.

Under a heavy layer 7 attack, ingress controller CPU or connection limits can become critical.

Ingress telemetry must therefore be monitored in Kubernetes DDoS testing.

### DDoS Risk in Microservice Architectures

In microservice structures a single request can trigger several services.

For example:

API

↓

auth service

↓

order service

↓

payment service

↓

database

A single malicious request can create chained resource consumption.

DDoS risk must therefore be assessed not only at the public endpoint but at the internal service dependency level too.

### What Is Cascade Failure?

When one service becomes overloaded, other services can keep sending it requests.

This can create a chained collapse.

It is called **cascade failure**.

Circuit breaker and timeout mechanisms can reduce this risk.

### How Does a Circuit Breaker Help with Cloud DDoS?

A circuit breaker can temporarily halt calls when a particular downstream service keeps failing.

This prevents one service's failure causing other services to consume resources too.

It is important for resilience in cloud-native applications.

### Why Does Load Shedding Matter in the Cloud?

Rather than trying to process every request under attack, low-priority requests can be rejected.

For example;

reporting,

search,

anonymous content

can be temporarily limited.

Critical operations can be protected.

This approach also keeps cloud costs under control.

### Do Cloud Security Groups Provide DDoS Protection?

A security group or network firewall provides access control by;

port,

IP,

protocol.

But it is not the solution for large volumetric attacks on its own.

DDoS mitigation at the cloud provider edge may be needed in particular.

A security group mainly reduces the attack surface.

### Can Cloud NAT Become a DDoS Bottleneck?

Yes.

Cloud NAT services can have limits for;

connections,

throughput,

port allocation.

Under heavy traffic the NAT resource can be exhausted.

NAT capacity must therefore also be assessed in resilience testing for applications using outbound dependencies.

### Why Do Cloud Egress Costs Matter in DDoS?

Data transfer charges can form a significant cost in cloud environments.

Heavy egress traffic during a DDoS attack can raise costs.

Monitoring must therefore cover not only compute but cost metrics such as;

network egress,

API usage,

storage operations.

### Is a Budget Alert a Security Control?

It does not block the attack directly.

But it matters for noticing EDoS risk early.

If normal daily cost is:

1,000 USD

and during the attack it reaches:

5,000 USD

an alert can be raised.

That gives a signal to the SOC and FinOps teams.

### The Relationship Between FinOps and DDoS Security

**FinOps** focuses on monitoring and optimising cloud costs.

Because DDoS attacks can affect cloud costs, FinOps data is valuable for security too.

In particular;

an abnormal compute increase,

traffic cost,

API usage,

serverless invocations

can each be a cyber security anomaly.

### How Is Cloud DDoS Detection Carried Out?

Several telemetry sources can be used.

For example;

cloud load balancer metrics,

WAF logs,

CDN telemetry,

flow logs,

API gateway logs,

application monitoring,

cost anomalies

can be assessed together.

This data can be correlated through a SIEM or XDR.

### What Are Cloud Flow Logs?

Flow logs on cloud platforms provide summary data about network traffic.

For example;

source IP,

destination IP,

port,

protocol,

traffic volume

can be analysed.

They help understand source diversity and traffic behaviour during a DDoS attack.

### What Should a Cloud SOC Monitor During a DDoS Attack?

The SOC can monitor these areas:

#### Traffic anomaly

Abnormal bandwidth.

#### WAF alerts

Layer 7 attacks.

#### API request spike

A sudden API load.

#### Autoscaling events

Unexpected instance growth.

#### Cost anomaly

A cost increase.

#### Application error

The 5xx rate.

These signals must be assessed together.

### Can Cloud DDoS Coincide with Account Compromise?

Yes.

DDoS is sometimes used to keep security teams busy while other attacks are carried out.

The SOC must therefore not focus on the traffic attack alone.

Signals such as;

IAM changes,

suspicious logins,

credential abuse,

data access

must be monitored at the same time.

### How Is Cloud DDoS Testing Carried Out?

Before running a DDoS test in a cloud environment, the relevant cloud provider's policies must be checked.

The test scope can assess;

public endpoints,

the load balancer,

the WAF,

the API gateway,

autoscaling,

the application backend.

The test must be increased gradually and under control.

### Why Do Cloud Provider Test Policies Matter?

Cloud providers apply particular rules to certain traffic tests.

Unauthorised or unplanned high traffic can trigger the platform's abuse mechanisms.

Before the test, therefore;

provider policy,

scope,

traffic limits,

the approval process

must be verified.

### Which Metrics Should Be Measured in Cloud DDoS Testing?

For example;

#### Requests Per Second

#### Load Balancer Latency

#### WAF Block Rate

#### Application CPU

#### Autoscaling Speed

#### Instance Count

#### Database Load

#### Cloud Cost Increase

#### Error Rate

#### Mitigation Time

can all be measured.

In the cloud, cost and scaling metrics matter alongside the classic Gbps figures.

### What Should a Cloud DDoS Report Contain?

A professional report can include these areas:

#### Cloud Architecture Overview

The architecture tested.

#### Public Attack Surface

Internet-facing resources.

#### DDoS Protection Controls

WAF, CDN and cloud-native protection.

#### Traffic Results

Gbps/PPS/RPS results.

#### Autoscaling Behavior

Scale-up and scale-down times.

#### Cost Impact

The attack's economic impact.

#### Application Performance

Response time and error rate.

#### Detection Timeline

SOC and cloud security alert times.

#### Remediation

Improvement recommendations.

### Multi-Cloud DDoS Resilience

Some organisations use several platforms rather than a single cloud provider.

This approach can reduce vendor dependency risk.

But multi-cloud creates new difficulties such as;

routing,

identity,

data synchronisation,

operational complexity.

For DDoS, multi-cloud provides real resilience only when designed correctly.

### Hybrid Cloud DDoS

Many organisations use both on-premise and cloud environments.

Attack traffic can then create different effects across;

the cloud application,

the data centre,

the VPN,

private connectivity.

In a hybrid architecture the anti-DDoS strategy must cover every traffic path.

### Cloud DDoS and Business Continuity

Using the cloud can provide high availability.

But business continuity must still be planned.

For example;

what happens if the primary region becomes unreachable?

Does DNS failover work?

Is the secondary region ready?

Is database replication sufficient?

Is the RTO met?

These questions are the foundation of cloud DDoS resilience.

### What Is the Biggest Mistake in Cloud DDoS Protection?

One of the most common mistakes is the assumption:

**“We're in the cloud, we don't have a DDoS problem.”**

The cloud provider can offer strong protection at the network layer.

But the organisation's;

application design,

API rate limits,

origin exposure,

autoscaling,

cost controls

may be weak.

Cloud DDoS security must therefore be handled through shared responsibility.

### What Does Shared Responsibility Mean for DDoS?

The cloud provider can protect certain layers of the infrastructure.

But a significant part of the application and configuration responsibility sits with the customer.

The provider can absorb a large volumetric attack, for instance.

But if the organisation's login endpoint exhausts the database at low RPS, that is an application design problem.

The division of responsibility must therefore be clearly understood.

### How Can Cloud DDoS Protection Be Strengthened?

These controls can be assessed in a corporate cloud architecture:

#### Cloud-Native DDoS Protection

Traffic protection at the provider level.

#### CDN

Edge distribution.

#### WAF

Layer 7 filtering.

#### API Gateway

Rate limiting and quotas.

#### Origin Protection

Reducing direct access to the backend.

#### Autoscaling

Controlled capacity growth.

#### Budget Controls

Monitoring EDoS risk.

#### Multi-Region

Failover and distribution.

#### SIEM/SOC Integration

Central visibility.

### How Should Rate Limiting Be Designed for the Cloud?

Rather than IP-based limits alone, limits can be applied by;

user,

API key,

session,

tenant,

endpoint.

Each customer can have a different quota, for instance.

This approach reduces the impact of distributed attacks.

### What Is Tenant-Based Rate Limiting?

In SaaS applications, one customer's excessive usage must not affect other customers.

**Tenant-based rate limiting** can therefore be applied.

A particular resource quota is set for each tenant.

Even if one tenant generates excessive traffic, the other tenants' service is protected.

This is also a multi-tenant resilience approach.

### Why Do Resource Quotas Matter?

In cloud-native systems, limits can be placed on;

CPU,

memory,

API requests,

database connections.

The aim is to prevent a single service or user consuming the platform's entire resources.

This approach is valuable for DDoS and abuse resilience.

### The Relationship Between Cloud DDoS and Zero Trust

Zero Trust is not a direct DDoS solution.

But removing critical management services from the public internet reduces the attack surface.

For example;

the admin panel,

the management API,

the database interface

can be used only over a private network or through identity-aware access.

The number of public services the attacker can target thereby falls.

### Cloud DDoS Resilience Score

An organisation can score its cloud DDoS maturity across different areas:

#### Network Protection

#### Application Protection

#### API Security

#### DNS Resilience

#### Autoscaling

#### Cost Protection

#### Multi-Region Readiness

#### SOC Visibility

This approach makes it easier to track progress over time.

### Conclusion: Moving to the Cloud Does Not Remove DDoS Risk, It Changes Its Shape

Cloud infrastructure can provide important advantages against DDoS attacks.

Global network capacity,

anycast,

automatic scaling,

cloud-native protection

are strong defensive layers.

But these capabilities must not create a false sense of security.

In a cloud environment the attack can target;

the public IP,

the load balancer,

the API gateway,

the authentication service,

the Kubernetes ingress,

the database,

a serverless function.

And even if the system does not fail entirely, the attack can raise costs significantly.

In cloud DDoS security, therefore, the only question should not be:

**“Is the service up?”**

These must also be measured:

#### What happens to response time under attack?

#### How quickly does autoscaling engage?

#### Can the WAF separate out malicious traffic?

#### Are the API rate limits working correctly?

#### Is the origin directly reachable?

#### How much does the cloud cost rise?

#### How long does the SOC take to notice the attack?

Cloud DDoS resilience can only be genuinely measured when network, application, identity, scaling and cost controls are assessed together.

But cloud or not, most internet services share one dependency:

**DNS.**

The web server may be running.

The API may be healthy.

The cloud region may be entirely up.

But if DNS does not respond, the user cannot reach the service.

DNS infrastructure must therefore be treated as a separate critical target in DDoS attacks.