An Introduction to Web Application Security

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What Is Web Application Security?

Web application security is the notion of protecting web applications, web services such as APIs, and web servers from attack by building security controls that help websites function as designed, even under attack. Like any software, web applications have defects. Some are real vulnerabilities that can introduce risk to organizations and be exploited.

Web application security resolves these potentially harmful defects by implementing security measures and leveraging secure development practices throughout the software development life cycle (SDLC). Improving web application security addresses implementation-level flaws and design-level bugs.

Web application data security is crucial to protecting customers, their data, and organizations of all sizes from cybercrime including data theft. Cloud web application security architecture spans multiple layers in the cloud, which means it is vulnerable at various points.

Cloud web application API security delivers both distributed cloud protection for a web application and API security specifically, along with bot protection and other security for distributed apps and APIs across edge sites and in the cloud.

Web Application Security Basics

Many types of web application security threats exist, ranging from large-scale network disruptions to targeted manipulation of databases. The Open Web Application Security Project (OWASP) Top 10 list names the ten most critical web application security risks most likely to harm applications in production.

However, even beyond the OWASP top 10 web application security risks, numerous threats can affect software applications and web application cyber security. Here are some of the most common web application security vulnerabilities:

Injection vulnerabilities

Injection vulnerabilities such as cross site scripting (XSS) and SQL injection allow threat actors to deliver malicious data to be executed on the web application server. XSS vulnerabilities are common web application security issues that allow attackers to inject client-side scripts into a webpage to access important information directly or impersonate and trick the user into revealing important information. Attackers use SQL injection to exploit application vulnerabilities to gain access to unauthorized information, modify or create new user permissions, or otherwise access sensitive data.

Denial-of-service (DoS) and distributed denial-of-service (DDoS) attacks

Denial-of-service (DoS) and distributed denial-of-service (DDoS) attacks are web application security issues that enable attackers to overwhelm a targeted server and its surrounding infrastructure with a variety of attack traffic and vectors. Eventually, the target server is slow and sluggish and cannot process requests effectively, denying service to the incoming requests of legitimate users.

Broken access control

Broken access control is among the most common web application security breaches and allows users to gain unauthorized access and privileges. Most often, broken access control enables attackers to act as administrators or regular users or grants unauthorized privileged functions.

Cryptographic failures

Cryptographic failures—sometimes referred to as sensitive data exposures—occur when data is improperly protected at rest and in transit, exposing sensitive data such as passwords, credit card numbers, and health records. These web application security challenges can lead to non-compliance with financial standards like PCI Data Security Standards (PCI DSS) and data privacy regulations such as the EU General Data Protection Regulation (GDPR).

Insecure design

Insecure design covers missing or ineffective security controls that cause more frequent web application security attacks. Secure design can remediate implementation flaws in applications, but no amount of configuration or remediation can repair insecure design.

Security misconfigurations

Security misconfigurations such as XML external entities (XXE) vulnerabilities occur due to a lack of security hardening across the application stack. Other common security misconfigurations that give rise to web application security concerns include unrequired features that remain installed or enabled, cloud service permissions that are improperly configured, or admin accounts or default passwords left in place.

Vulnerable and outdated components

Vulnerable and outdated components are another class of common security threats for web applications that includes unsupported or outdated software. This commonly happens when using or building on applications without complete knowledge of versions and internal components.

Server-side request forgery (SSRF) vulnerabilities

Server-side request forgery (SSRF) vulnerabilities are challenges to web application security that occur when a web application fails to validate user input URLs before pulling data from remote resources.

Advantages of Web Application Security

Why is web application security important? Active web application security testing aims to detect security vulnerabilities in web applications and their configuration. Web application security targets the application layer to provoke the system to behave in unexpected ways and uncover unusual system errors unpredicted at the design stage.

However, the overall goal of managing web application security is to ensure that exposed functions in the web application are—and remain—secure. This is why web application security is important: it tests implemented security features inside the application such as authorization as well as secure implementation of other features such as business logic and input validation. Other benefits of web application security include reduced risk from insiders and enhanced protection of sensitive data.

Web Application Security Best Practices

What are the best practices for web application security?

Perform a threat assessment

Perform a threat assessment to know how specifically to enhance organizational web application security standards. Create a list of sensitive assets, consider the range of threats that face them, what methods a hacker might use to compromise your application, existing security measures, and how to mitigate threats with defensive measures and/or additional tools.

Shift security left

Web application development security best practices suggest transitioning from annual product releases to more frequent releases, and making security testing part of the development cycle to accommodate this change. Automated web application security tools in the CI/CD pipeline enable rapid repair of issues soon after release.

Prioritize remediation

Prioritize remediation based on severity and a threat assessment determined by common vulnerability scoring system (CVSS) ratings and other criteria. Confirm whether proprietary code is using vulnerable open source components. If the product never invokes the function of the vulnerable component, its CVSS rating remains significant, yet there is neither risk nor impact.

Web application security monitoring

Measure and report application security program success by identifying the metrics that key stakeholders prioritize and present results in an actionable, clear format to achieve buy-in.

Manage privileges

Limit privileges, especially for sensitive and mission-critical systems, based on the least privilege principle. This means access to data and applications is limited to only those who need them, at the time they need access to them.

Use a WAF

A web application firewall (WAF) is among the most important web application security features. A WAF creates a filtration barrier between a targeted server/web application and malicious HTTP traffic. In this way, the WAF intercepts attacks like cross site scripting, cross site forgery, and SQL injection.

How to Test Web Application Security: Application Security Testing

Application Security Testing (AST) is a process of identifying and remediating security vulnerabilities to help make applications more resilient to security threats. AST involves tools that can identify source code vulnerabilities and test applications for runtime security weaknesses as well as network vulnerability scanners.

Here are some common types of web application security testing:

Black box security testing

In a black box test, the tester takes the outside attacker’s perspective and the testing system lacks access to the internal system. A human tester or testing tool must actively discover vulnerabilities during reconnaissance, which allows identification of systems to be tested, but cannot test underlying application security weaknesses.

White box security testing

A white box test grants the testing system complete internal access to the tested application. Static code analysis is a classic example of white-box testing as is dynamic testing. White box testing is often used to identify issues with code quality, vulnerabilities in business logic, insecure coding, and security misconfigurations. However, not all vulnerabilities are truly exploitable in production environments—a real downside to the white-box approach.

Gray box security testing

A gray-box test seeks to strike a balance between white and black box models and offers a hybrid approach with the testing system having access to limited information on the tested application. For example, the tester might take the perspective of a signed-in user with provided login credentials so they can test the application and analyze privileged access. Gray box tests can simulate attackers who are already inside the network perimeter or other insider threats.

Dynamic application security test (DAST)

DAST is an automated form of application security testing. Used alone DAST is ideal for ensuring low-risk, internally facing applications comply with regulatory security assessments. For critical applications undergoing minor changes and other applications of medium-risk, it is best to combine DAST with manual web security testing for common vulnerabilities.

Static application security test (SAST)

SAST provides manual and automated testing techniques for identifying bugs in a production environment. It also allows developers to systematically scan source code to eliminate security vulnerabilities in software.

Interactive application security test (IAST)

IAST tools employ DAST and SAST tools and methods to detect a wider range of security issues. These tools run dynamically to inspect software during runtime to determine the root cause of vulnerabilities. This helps developers identify specific lines of affected code to better understand how to ensure security in web applications. IAST tools are also useful in API testing.

Mobile application security testing (MAST)

MAST tools test mobile application security using various techniques involving dynamic and static analysis and forensic data investigation. Organizations check security vulnerabilities with MAST tools and monitor mobile-specific issues, such as data leakage, jailbreaking, and malicious WiFi networks.

Penetration testing

This manual application security test is ideal for critical applications, particularly those undergoing big changes. The assessment involves adversary-based testing and deployment of business logic to identify advanced attack scenarios.

Runtime application self protection (RASP)

The RASP technology and security approach is an evolving technique for applications that encompasses various web application security principles and technological techniques aimed at monitoring and blocking attacks in real-time. RASP technology can analyze application traffic and user behavior at runtime to help prevent cyber threats by achieving visibility into application vulnerabilities and exploited security weaknesses.

Software composition analysis (SCA)

SCA tools generate an inventory of third-party commercial and open source components used inside software to identify which versions and components are actively used. Organizations use SCA tools to find security vulnerabilities contained in these third-party components.

Cloud native application protection platform (CNAPP)

A CNAPP unites tools needed to protect cloud native applications in a centralized control panel and unifies cloud security posture management (CSPM) and cloud workload protection platform (CWPP) with other capabilities. Container orchestration platforms such as Kubernetes often deploy CNAPP technology to incorporate API discovery and protection, identity entitlement management, and automation and orchestration security for containers.

Web Application Security Solutions

Various web application security testing and security approaches address different vulnerabilities.

Web application security software such as firewalls, web application firewalls (WAF), and intrusion prevention systems (IPS), are basic tools in this space. Among the more advanced web application security tools, web application firewalls (WAFs) monitor and filter traffic between users and the web application to defend against many types of attacks. A WAF is configured with policies that help analyze traffic, block unsafe traffic, and stop the app from leaking data.

Several other techniques for promoting security and building secure web applications throughout the software development lifecycle (SDLC) include:

  • Introduce web application security testing tools and security standards during the design and application development phases.
  • Protect applications in production environments with continuous web application security assessment.
  • Implement strong authentication and web application security services for any mission-critical applications or any that contain sensitive data.
  • Other web application security products and techniques include app vulnerability scanners, access management and user authentication, cookie management, IP denylists, and traffic visibility.

Does Avi Offer Web Application Security?

Traditional web application security solutions such as appliance-based web application firewalls (WAFs are rigid to scale, complex to manage, require costly overprovisioning to compensate for lack of elasticity, and lack application security insights. Along with growing numbers and severity of web application attacks, these web application security challenges have increased the need for a modern, secure web application framework critical for today’s enterprise.

In contrast to traditional hardware-based solutions, Avi’s Web App Security is a comprehensive Web Application and API Protection solution that delivers network and application security with a context-aware web application firewall (WAF) to protect against all forms of digital threats.

Avi’s Web App Security solution offers:

  • Positive security with WAF learning mode
  • Real-time app security insights
  • Centralized application security management


Learn more about Avi’s web application security platform here.

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