Web Application Security 101: Threats, Targets & Protection

What is Web Application Security?

Web application security refers to the implementation of strategies, technologies, and practices designed to protect web applications from cyber threats. It involves securing applications from unauthorized access, data breaches, and exploitation of vulnerabilities.

Why Web Applications are a Prime Target for Cyberattacks

Web applications remain a top target for cybercriminals due to their accessibility, valuable data, and security gaps. Alarmingly, 75% of applications in financial services, retail, and the public sector have unpatched vulnerabilities that persist for over a year, leaving them exposed to exploitation. Attackers actively seek out these weaknesses to infiltrate systems, steal sensitive data, and disrupt operations.

Key reasons why web applications are highly targeted:

• High Data Value: Web applications store sensitive data, including personal and financial information.
• Public Accessibility: Unlike internal networks, web applications are exposed to the internet, making them easy targets.
• Rapid Development Cycles: Frequent updates and continuous deployments may introduce security vulnerabilities.
• Complex Attack Surface: APIs, third-party integrations, and user inputs create multiple entry points for attackers. Check the best practices to reduce the attack surface.

Common Web Application Security Risks

Web applications face numerous security threats, many of which are outlined in the OWASP Top 10, a globally recognized list of the most critical security risks for web applications. These risks highlight vulnerabilities that attackers commonly exploit, emphasizing the importance of proactive security measures.

Injection Attacks (SQL Injection, Command Injection)

Injection attacks occur when an attacker sends malicious code through input fields to manipulate backend databases or system commands. SQL Injection allows attackers to extract or modify sensitive data, while Command Injection enables the execution of arbitrary system commands, potentially leading to full system compromise.

Cross-Site Scripting (XSS)

XSS attacks involve injecting malicious scripts into web pages that are then executed in a user’s browser. This allows attackers to steal session cookies, redirect users to malicious sites, or deface web content. XSS vulnerabilities often arise from improper input sanitization and output encoding.

Broken Authentication and Session Management

Inadequate authentication and session management can grant unauthorized access to user accounts. Attackers can exploit stolen credentials, session hijacking, or weak password policies to take over user accounts and gain access to sensitive data.

Security Misconfigurations

Many security breaches occur due to misconfigured settings, such as default credentials, overly permissive access controls, or exposed debug information. Poorly configured applications, databases, or cloud environments leave sensitive data unprotected and increase the risk of exploitation.

DoS and DDoS Attacks

In DoS and DDoS attacks, cybercriminals flood web applications with excessive traffic to overwhelm server resources, causing performance degradation or complete service downtime. These attacks can be carried out using botnets, making them difficult to mitigate without specialized security measures.

Sensitive Data Exposure

Sensitive data, such as login credentials, financial information, and personal records, must be securely stored and transmitted. Insufficient encryption, weak hashing mechanisms, and improper access controls can lead to unauthorized access, resulting in data breaches and compliance violations.

Cross-Site Request Forgery (CSRF)

CSRF attacks manipulate authenticated users into performing unintended actions on a web application. By exploiting trust-based session handling, attackers can manipulate transactions, change user settings, or initiate fund transfers without the victim’s consent.

Insecure APIs

APIs are a crucial component of modern web applications, but insecure API implementations can expose sensitive data, allow unauthorized access, and serve as an entry point for attacks. Weak authentication, excessive data exposure, and improper access controls are common security flaws that attackers exploit to compromise APIs.

To learn more about how a WAF prevents top security threats, check out this blog on the top threats a WAF mitigates.

Key Components of Web Application Security

Vulnerability Scanner

A vulnerability scanner is an automated tool that scans web applications for known security flaws. It helps organizations identify issues such as misconfigurations, outdated software, weak authentication mechanisms, and vulnerabilities listed in the OWASP Top 10.

Automated web vulnerability scanners play a crucial role in identifying security weaknesses in web applications by simulating real-world attack scenarios. These scanners help organizations proactively detect and mitigate vulnerabilities before attackers exploit them.

Key Benefits of Web Application Scanners:

• Comprehensive Coverage: Scans for known vulnerabilities, including OWASP Top 10 threats, misconfigurations, and weak authentication mechanisms.
• Efficiency and Scalability: Automated scans cover large applications quickly, reducing manual effort and enhancing security posture.
• Accuracy with AI/ML Integration: Advanced scanners leverage artificial intelligence and machine learning to minimize false positives and detect sophisticated threats.
• Continuous Monitoring: Provides real-time vulnerability assessments, ensuring that security gaps are promptly identified and fixed.
• Risk Prioritization: Scanners categorize vulnerabilities based on severity (critical, high, medium, low), allowing security teams to focus on fixing the most dangerous ones first.
• Integration with Security Tools: Modern scanners integrate WAF to provide real-time protection against identified threats, blocking attacks before they reach the application.
• Secure DevOps (DevSecOps) Adoption – By integrating with CI/CD pipelines, scanners help developers find and fix vulnerabilities early in the development cycle, reducing security risks before deployment.
• Compliance Readiness – Many security standards mandate periodic vulnerability assessments to ensure a secure environment:
• • PCI DSS Requirement 11.2 – Requires quarterly vulnerability scans and after significant changes to the environment.
  • HIPAA (45 CFR §164.308(a)(8)) – Mandates regular technical evaluations to ensure continued protection against risks.
  • ISO 27001: A.12.6.1 – Calls for regular vulnerability assessments and patch management.

Vulnerability scanners help businesses meet these compliance requirements by generating detailed reports on security gaps and remediation steps.

While vulnerability scanners are essential for identifying security risks, they cannot simulate real-world attacks or detect complex business logic flaws, which is where penetration testing comes in.

Penetration Testing

Penetration testing (pen testing) is a proactive security assessment where ethical hackers simulate real-world attacks to uncover deeper vulnerabilities.

How Pen Testing Enhances Security

• Identifies Business Logic Flaws: Detects issues that automated scanners might miss, such as broken access controls and improper session management.
• Validates Exploitability: Helps security teams understand how vulnerabilities could be exploited in an actual attack.
• Provides Actionable Remediation Steps: Offers tailored recommendations for patching security gaps based on the test results.

While vulnerability scanners and pen testing help detect and validate security flaws, organizations also need to prevent attacks in real time. Many assume that traditional firewalls provide this protection—but that’s not entirely true.

Why Network Firewalls Are Not Enough

Traditional network firewalls are designed to protect network infrastructure by filtering traffic based on IP addresses, ports, and protocols. However, they are ineffective in securing web applications because:

• Limited Traffic Inspection: Network firewalls primarily analyze packet headers and cannot inspect the content of web requests for malicious payloads.
• Inability to Detect Web-Based Attacks: Attacks like SQL injection, XSS, and CSRF occur at the application layer, beyond the scope of traditional firewalls.
• Lack of Granular Protection: Web applications require deeper analysis of HTTP and HTTPS traffic, user inputs, and API interactions.
• Dynamic Nature of Web Threats: Attackers continuously evolve their techniques, requiring adaptive security solutions beyond static firewall rules.

To address these challenges, businesses must deploy WAFs alongside traditional network firewalls to provide comprehensive security. Read this detailed comparison of WAF vs. Firewall to understand their differences.

Learn more about essential Application Security Best Practices to strengthen your defences.

Role of Web Application Firewall (WAF) in Protection

A Web Application Firewall (WAF) protects web applications by monitoring, filtering, and blocking malicious traffic before it reaches the application server.

A WAF operates at Layer 7 (Application Layer) of the OSI model, allowing it to inspect HTTP/S requests, analyze payloads, and enforce security policies. It utilizes signature-based detection, behavior analysis, rate limiting, machine learning models, and real-time threat intelligence to mitigate risks.

Real-Time Threat Detection and Mitigation

How WAF Identifies Malicious Requests

• Deep Packet Inspection (DPI) – A WAF examines HTTP/S traffic at the request and response level, analyzing headers, cookies, parameters, and payloads to detect malicious patterns.
• Signature-Based Detection – The WAF uses a database of known attack signatures to identify and block common threats like SQL injection, XSS, and Remote Code Execution (RCE).
• Anomaly-Based Detection – Machine learning algorithms and behavioral analysis help identify deviations from normal traffic patterns, flagging unknown threats such as zero-day exploits.
• Geo-IP Filtering – Blocks or restricts traffic from high-risk locations based on IP reputation data.
• Rate Limiting & Throttling – Prevents abuse by limiting the number of requests from a single IP address in a given timeframe.

Example: SQL Injection Mitigation

The WAF analyzes user input and blocks queries that contain suspicious SQL commands like UNION SELECT or ‘ OR 1=1 –.

It uses parameterized query enforcement to prevent attackers from injecting SQL payloads into database queries.

Learn more about how a WAF blocks malicious requests in our blog on how a WAF works.

Virtual Patching for Unpatched Vulnerabilities

Organizations often struggle to patch vulnerabilities due to business constraints, legacy applications, or third-party dependencies. A WAF helps by applying virtual patches at the network edge.

How Virtual Patching Works:

• Threat Intelligence Feeds: The WAF continuously updates its database with the latest vulnerability and exploit data from sources like OWASP, MITRE ATT&CK, and threat intelligence providers.
• Custom Security Rules: Managed WAF security teams create tailored rules to block exploit attempts targeting specific vulnerabilities.
• Behavioral Monitoring: The WAF detects unusual request patterns and automatically applies mitigation measures, such as blocking requests or triggering alerts.
• Webhooks & SIEM Integration: Virtual patching events are logged and can be integrated with SIEM (Security Information and Event Management) systems for deeper analysis.

Example: CVE-2023-51467, a critical authentication bypass vulnerability in Apache OFBiz

Attackers exploited a zero-day authentication bypass vulnerability in Apache OFBiz, allowing unauthenticated access and potential remote code execution.

Before an official patch was available, the WAF successfully blocked exploit attempts with virtual patching. See how AppTrana mitigates this flaw.

Security Analytics & Threat Intelligence

A modern WAF provides real-time insights into attack patterns, vulnerabilities, and security incidents through dashboards, logs, and SIEM integration.

Key Analytics Features:

• Attack Trends Dashboard – Displays real-time and historical data on attack types, sources, and frequency.
• Threat Intelligence Feeds – Correlates incoming threats with global cyber threat databases.
• Forensic Logging & Packet Capture – Stores request/response data for post-incident analysis.
• Geo-Blocking & Traffic Segmentation – Allows blocking of traffic from specific regions or ASN providers.

Seamless Integration with Security Ecosystem

A WAF enhances overall cybersecurity by integrating with:

• Vulnerability Scanners (Indusface WAS) – Blocks threats detected by scanning tools.
• SIEM Systems (Splunk, IBM QRadar, ArcSight) – Sends logs for security event correlation.
• Identity & Access Management (IAM) – Works with SSO, MFA, and JWT-based authentication.
• DevSecOps Pipelines (CI/CD) – Provides security policies for containerized and serverless applications.

AppTrana WAAP integrates an inbuilt DAST scanner, which continuously scans the web application for known and emerging vulnerabilities and provides insights to enhance WAF policy enforcement. The results from AppTrana’s DAST scanner can be reviewed by security experts, who fine-tune WAF policies to ensure zero false postives.

Ensure your web application security is robust by following this Application Security Checklist, covering essential steps for vulnerability management, threat mitigation, and compliance readiness.