As hacking threats evolve in complexity, securing your web applications feels like an uphill battle. Between keeping software updated, monitoring for misconfigurations, and analyzing traffic patterns, it’s a lot to juggle. This complexity only increases exponentially when you move web apps to the cloud.

With more attack surfaces and data now outside your firewall, you absolutely need to re-evaluate security in a cloud context. But don’t panic! While the cloud introduces new risks, providers also give you powerful tools to lock things down.

Follow cloud-focused security best practices, and your organization can confidently reap benefits like scalability and cost savings without compromising safety. This guide explores the top challenges you’ll face along with tactical measures for protecting cloud-hosted apps and data. 

Key Security Challenges in Cloud Environments

Adopting cloud computing certainly provides advantages, but you also need to be aware of the new attack surfaces and vulnerabilities you may be exposed to.

Shared Responsibility Model

In the cloud, providers like AWS and Azure are responsible for securing the underlying infrastructure and hardware. But you are responsible for securing everything deployed on top – including web apps, data, and cloud configuration. This “shared responsibility” model means you carry more weight for cloud security than you think.

For example, misconfiguring a cloud database to allow public access could expose sensitive customer data. The provider secured the database software and infrastructure, but you were responsible for the database access permissions. 

Increased Attack Surface

By nature, cloud environments have more points of entry spread across more services and users. Take AWS – with its over 200 services, each component and connection between components represents a potential attack vector. As you deploy more cloud resources, you increase the “blast radius” hackers could exploit to breach other parts of your infrastructure if not properly locked down.

Yet, despite these risks, 66% of organizations currently use more than 25 SaaS applications. It’s not much of a surprise that 44% of them have experienced a cloud data breach at some point. 

Data Security and Privacy Concerns

Migrating data to the cloud necessarily means relinquishing physical control. You risk exposing sensitive customer and internal business data without proper encryption and access controls.

Hackers have lots of motivations for targeting weakly protected cloud data stores – from accessing usernames/passwords for broader identity theft, to holding databases for ransomware attacks against your organization.

Not addressing cloud data security could land you in legal hot water as well. Remember that you are liable for any data mishandled or exposed by cloud providers under most regulatory compliance frameworks like HIPAA and PCI DSS.

Essential Security Measures for Cloud-Based Web Apps

So, now that you understand the primary cloud security challenges, what can you actually do about them? Here are four essential measures you should implement right away to protect your cloud-hosted web apps:

Secure Cloud Configuration and Access Control

Properly configuring cloud resources is at the heart of the “shared responsibility” model. Make security and access control central to your cloud infrastructure strategy from day one.

For each cloud component and service, apply strict permissions and monitor closely for misconfigurations that could unintentionally expose data. Double-check settings like S3 buckets and database connections that are internet-facing by default.

Tools like AWS Config and Azure Policy help systematically enforce and validate proper security configurations across cloud environments at scale. Make use of them.

Web Application Firewalls (WAFs)

Deploying a robust Web Application Firewall (WAF) should be a cornerstone of your cloud security strategy. WAFs act as protective barriers for web apps by filtering incoming HTTP/HTTPS traffic and blocking common web-focused attacks.

Your standard firewalls and network security groups configured at the infrastructure level can’t provide application-layer protection against attacks targeting vulnerabilities in code or web-visible inputs. That’s where WAFs come in – they “understand” web traffic to filter malicious payloads designed to exploit web apps specifically.

For example, a cloud WAF can detect and prohibit attempts to inject malicious SQL commands in input fields that could trick the database behind your web app. Or it can stop cross-site scripting (XSS) attacks that try to inject browser-executable JavaScript into responses rendered by your app’s front end. Unfortunately, these and other “Layer 7” attacks are quite common but readily defended against by WAF policies once you have them in place.

Another major benefit of WAFs in the cloud is protection against distributed denial-of-service (DDoS) attacks—those frustrating bandwidth-flooding events that can bring your web services to their knees. By absorbing and dispersing excess traffic volumes before they reach your apps, a cloud-based WAF acts like a bodyguard, taking the brunt of attacks on your behalf.

Vulnerability Management and Patching

Hackers have become proficient at chaining exploits against known vulnerabilities in web frameworks like Struts and common dependencies. Actively monitoring all software components and libraries for patches prevents attackers from gaining an easy foothold into your web apps.

Cloud services increasingly automate vulnerability tracking and patching workflows – use them rather than relying on manual efforts. AWS Inspector, for example, regularly scans deployments for common issues and vulnerabilities across application stacks, operating systems, and databases.

Data Encryption at Rest and in Transit

Encrypt sensitive web app data while storing “at rest” in databases and cloud storage buckets and moving “in transit” across networks. Proper encryption is the last defense line if other perimeter security measures fail.

Apply database and object-level encryption rather than relying on transport encryption during data transfers. AWS and Azure make applying robust encryption more convenient than most organizations can achieve – so take advantage of native capabilities.

Taking Control of Your Cloud Security Posture

The cloud security best practices I outlined are just the beginning. Here are some additional priority areas you should address:

Centralize Identity and Access Management

The expanding cloud attack surface makes managing identities and access that much more critical. To limit breach impact, centralize identity through single sign-on rather than individual credentials per service.

Apply the principle of least privilege to permission user access, and leverage multi-factor authentication for all cloud admin accounts. Tools like Azure Active Directory and AWS IAM let you manage access at scale.

Institute Data Loss Prevention Controls

Preventing data exfiltration should be a top concern when shifting to the cloud. Data loss prevention (DLP) solutions analyze and automatically block sensitive data like credit card numbers from leaving environments.

Integrate DLP capabilities at multiple layers when handling regulated data or IP – into data warehouses, web application firewall rules, cloud storage permissions, and endpoint agents.

Architect with Security in Mind

Rather than bolting on security as an afterthought, bake it into the design of cloud architectures from the initial build phase.

Segmentation, protection of sensitive data flows, logging, and compliance auditing need to be structural components of technology stacks – not tacked on at the end where visibility and control are limited.

Promote Security Training for Cloud Teams

Your own staff likely poses the biggest insider threat as they interact with cloud environments daily. Expand security training to cover common cloud risks, proper access permissions, and data handling so mistakes don’t turn into breaches.

Include developers, engineers, data analysts, and operators that help manage cloud infrastructure and web architectures.

Final Word

The bottom line is that comprehensively securing cloud environments requires thinking beyond just checking boxes on common best practices. Continually assess additional focus areas – from deeper identity lifecycle management to compliance automation and disaster recovery preparedness – as part of your cloud security strategy.