Java Web App Security​: Everything You Need to Know

Java is famous for its wide usage in enterprise environments, financial systems and ecommerce platforms, so undoubtedly its security is of vital importance. In this article, we’ll explore the critical aspects of Java web application security, from factors that can weaken security in Java web applications​ and the most common vulnerabilities to Java features that affect application security, and popular Java security tools.

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Why Do You Need a Secure Programming Language?

As we all rely on web apps that often store sensitive data — be they for business or our personal daily life — security has become a cornerstone of software development. According to Statista, the cybersecurity market will have a steady annual growth rate of 7.58% from 2025 to 2029. A secure programming language like Java is the basis for the development of robust and functional applications that can withstand an always increasing number of modern cybersecurity threats. For many years Java application security​ has been recognized as high, and the language focused on features that are specifically designed to mitigate vulnerabilities.

Factors that Can Weaken Java Security

Although Java is famous for its rich safety potential, it is not completely immune to the certain dangerous practices and oversights. They can introduce vulnerabilities into your apps, so it is vital to understand and avoid these issues.

Outdated Java versions

If companies are eager to continue to use obsolete Java versions and are reluctant to introduce renovation and changes, it inadvertently leads to vulnerabilities in their systems. When they fail to upgrade timely, they expose the apps to known exploits that cyberattackers are happy to use. Also, older versions of Java do not have modern security enhancements and enhanced API.

Access control

Access control helps establish the definite parameters that specify which users, processes and services are allowed to interact with specific components of your application. If you manage such permissions improperly, it can lead to great security holes. Through them, unauthorized entities could read, modify and even delete sensitive data of your users. To reduce this potential attack surface, companies implement the principle of least privilege and each user only gets the minimum permissions necessary to perform their tasks.

Third-party libraries

Plenty of Java applications rely on external libraries and frameworks for accelerated development. These tools significantly boost productivity, but also come with hidden risks: the dangers may be encountered if the imported components have security flaws. Occasionally malicious cyberattackers scan for known vulnerabilities in widely used libraries and attempt to use this knowledge for their own benefit, so it’s crucial for development teams to regularly monitor and patch such weaknesses.

Serialization

By default the serialization process in Java poses security risks when it handles untrusted input. It happens because it may allow attackers to inject malicious code and create their own objects with dangerous states. Besides, cyberattackers may build destructive payloads that can execute arbitrary code in the app environment during deserialization and cause substantial harm. Programmers should shun default Java serialization for external inputs, use secure alternatives such as JSON or XML-based serialization libraries and always whitelist allowed classes during deserialization.

Outdated cryptography

Outdated or weak cryptographic algorithms put sensitive information at risk of interception or decryption by hackers. Companies should enhance their network communication with well-vetted protocols and libraries, and encrypt all data with modern algorithms. Remember to regularly review and update cryptographic configurations for alignment with current best practices.

Code injection flaws

The dangers of improper handling of untrusted data include injection attacks. They happen when user input is concatenated directly into queries or commands without proper sanitization and parameterization actions. Use parameterized queries, prepared statements, strict input validation and frameworks like JPA/Hibernate for risk mitigation. All these measures can significantly reduce the possibilities of injection attacks and boost your protection in the long run.

Unvalidated user input

Attackers might introduce corrupted or harmful inputs to manipulate parsing mechanisms and trigger system overloads. Bear in mind that proper input validation safeguards the integrity of both client-side and server-side operations. A comprehensive validation program guarantees that data is sanitized and conforms to specified formats prior to processing.

Improper use of reflection

Java reflection can be extremely powerful, as it enables programmers with a possibility to inspect and modify classes at runtime. However, don’t forget that reflection can also expose private fields or methods and bypass access controls. Every attacker who gains unauthorized access to reflection-based functionality can manipulate or execute code in previously unintended ways. We recommend you to limit the use of reflection to necessary scenarios, verify inputs and restrict reflective calls to trusted code pathways.

Lack of regular security updates

Java ecosystems frequently release security patches and updates which represent a significant step forward from previous versions and supersede them in functionality. Organizations that do not implement a regular patching strategy risk leaving dangerous vulnerabilities unaddressed. Conduct periodic security audits and adopt an automated patch management process to ensure that your Java environment remains up to date and properly protected.

Insufficiently secure configuration

Default or misconfigured settings can leave sensitive features exposed. For example, this may include weak default passwords for administrative consoles and unprotected application endpoints. Carry out a thorough review of your Java application’s configuration before deployment and perform periodic reviews to ensure that nothing in the system has been changed inadvertently.

The most common vulnerabilities in Java applications

The integrity of Java applications, if not protected properly, can be compromised. Below, we’ll dive into some of the most widespread risks that you should address to safeguard your apps.

SQL injection

One of the most common vulnerabilities is SQL Injection, which can occur when unsanitized or unvalidated data is inserted into SQL queries. According to Statista, it remained the leading source of web app vulnerabilities and accounted for 23% of critical risks. When using this technique, cyberattackers manipulate the data input and can change the queries’ structure to grant unauthorized access. This manipulation also can compromise data integrity and exfiltrate sensitive information that should be kept in strict confidence. You must adhere to the security best practices to prevent such dangers. Always validate and sanitize all kinds of user input with the help of server-side checks, comply with the principle of least privilege, and monitor logs to make sure there is no suspicious activity happening.

Cross-Site Scripting (XSS)

With Cross-Site Scripting (XSS), a pervasive security issue, hackers target specifically the client side. According to Statista, this vulnerability accounted for 19% of critical risks in cybersecurity. They inject a malicious script into otherwise legitimate web pages, which then can execute the victim’s browser and steal valuable information or even redirect users to malicious websites. Although these dangers are profound, there are tools to mitigate them. Programmers should remember to carry out output encoding and make sure that all the dynamic data is escaped properly. For this purpose, you can conduct regular security reviews and use libraries such as the OWASP Java Encoder Project, which filter and encode all user-generated content. Other tools include secure frameworks and template engines that use automation for output escape.

Broken authentication and session management

Broken authentication and session management still pose significant threats for web apps. With this vulnerability, attackers can hijack sessions, impersonate legitimate users, or escalate privileges. The causes often arise from mismanagement of session tokens, improper session expiration, or insufficient password protection. The ways to eliminate these risks include robust session controls, limited session lifetimes, revoked tokens upon logout, password hashing, strong password complexity rules, and multi-factor authentication. 

Sensitive data exposure

Huge amounts of personal data are stored on the web. Therefore, you should be particularly vigilant in order to protect your corporate data, the data of your employees and clients. Malicious actors who get access to such data can harvest valuable information and use it for identity theft or financial fraud, or even cause irreparable reputational damage. Java software engineers should rely on strong encryption both in transit and at rest and use a secure vault solution with strong access control. Ensuring compliance with security regulations, such as GDPR or PCI-DSS, which will guide best practices in protecting your data.

Security misconfiguration

Application servers, frameworks, or database servers can all equally be prone to security misconfigurations such as enabled default credentials, exposed unnecessary services, and unpatched libraries that have existing vulnerabilities. Attackers can use these weaknesses as an invitation for easy entry. To prevent this, you should adopt a “secure by default” stance and regularly review and harden configuration files, and do not forget about timely updates.

Deserialization vulnerabilities

Java has a built-in serialization mechanism, a powerful feature, which can surprisingly also open the door to serious vulnerabilities. Fortunately, this can happen only if you handle untrusted data and the app accepts serialized objects from external sources, and then deserializes them without checking. To mitigate this, you should avoid Java default serialization and choose safer data transfer formats like JSON and use special libraries such as Jackson that can accept only expected classes.

Improper input validation

Java-based applications that do not incorporate user input validation on a regular basis, are increasingly susceptible to various kinds of injection-based attacks. Strategy to combat these potential hazards includes substantial manual checks and deep integration of secure coding practices throughout the entire SDLC (Software Development Life Cycle). A so-called whitelist approach, where only known, valid formats and data values are permitted, can also be beneficial, as it provides stronger security than a blacklist approach.

Cross-Site Request Forgery (CSRF)

With Cross-Site Request Forgery (CSRF), the trust a web application places in a user’s browser is exploited. This happens when victims, who have been already authenticated to a Java app, trigger unwanted actions. For example, they could unintentionally change personal details and execute financial transactions just by visiting a malicious website. In blocking CSRF attacks, a defense-in-depth approach is needed, when the company combines token-based validation, referrer checks, and constant user training and education.

Privilege escalation

In some cases, an app allows users to perform actions far beyond their authorized permissions. It can happen if role definitions are ambiguous, authorization checks are inconsistent, and duties are inadequately separated. The measures against privilege escalation include regular role definition audition, the principle of least privilege, authorization validation. Another important measure is keeping special logs that track all sensitive actions and enable quick identification of abnormal activity with its subsequent investigation.

Insecure API endpoints

Oftentimes apps rely on RESTful APIs or microservices, which may open up attack vectors, as they are known to expose endpoints to external clients. Without proper security controls, intruders can gain access to restricted data and perform their destructive operations. For high defense, use input validation and output encoding, thoroughly monitor all API calls and unusual patterns, and implement rate limiting or throttling to limit brute-force or denial-of-service attempts. Besides, you can utilize API Gateways, which will help you centralize security policies and enforce authentication and authorization controls.

10 Java Features That Affect Application Security

Below, we’ll explore ten key Java features that influence general app security and provide a robust foundation for safe app building.

Popular Java Security Tools 

We also recommend you to leverage robust tools that are designed to detect and address vulnerabilities in the system. Below is a list of popular instruments that can help you to achieve this aim.

OWASP Dependency-Check

One of the widely adopted tools in the Open Web Application Security Project (OWASP) is Dependency-Check. It can find outdated components and publicly disclosed vulnerabilities in project dependencies. Dependency-Check scans the codebase and then provides a thorough report that highlights specific vulnerabilities and even identifies their level of severity that could potentially harm the app.

Checkmarx

A comprehensive security platform, Checkmarx, provides software composition analysis, dynamic and static app security testing, and also tracks vulnerabilities. Besides, the tool helps with continuous integration and automation and offers remediation management features. The tool can detect sensitive components and simulate real cyber hacker attacks.

Snyk

Snyk specializes in the discovery and fixing of vulnerable components in both custom code and open-source dependencies. It continuously monitors for vulnerabilities in real-time and integrates with IDEs, CLIs, and Git workflows. Besides, it has AI tools and can work with Java-based package managers like Maven and Gradle and substantially uses AI in its work.

SonarQube

SonarQube is much more than just a security tool, because it offers a holistic approach to code quality management. After thorough analysis of code, it provides comprehensive metrics on code quality, bugs and code smells. The unique Quality Gates feature guarantees that the code meets the high standards before the deployment stage. 

OpenText Fortify Static Code Analyzer

Fortify Static Code Analyzer is a robust static app security testing tool that was built to detect weaknesses in the source code. Its work is similar to those of a compiler, as it can convert code into an intermediate structure that is perfectly optimized for security analysis. Subsequently, the instrument applies specified rules and finds where they have been violated.

Burp Suite

Initially Burp Suite was famous as a web app security testing instrument, but it is extremely valuable for working with Java-based web apps as well. It is a versatile instrument, which helps to deal with such common threats as SQL injection, cross-site scripting and session hijacking.

FindBugs/SpotBugs

FindBugs, and its successor SpotBugs, are static analysis tools that were specifically created for Java apps. Not only can they be easily integrated with popular IDEs and build tools, but also they can lower false-positive rates, identify more than 400 bug patterns and flaws.

Tenable Nessus

This tool is not specific to Java coding. Nevertheless, it can be of use for finding potential compromises in Java, especially in a network context. It boasts of a comprehensive vulnerability database and supports various compliance standards. The tool also identifies misconfigurations and outdated software versions in apps and their hosting environments.

AppScan

AppScan comprises a large suite of AI-driven security testing tools. AppScan integrates with DevOps tools and processes and can perform cognitive analysis. From coding to production — it helps companies detect and solve issues with the security throughout the whole SDLC. 

Veracode

Veracode is a comprehensive application security platform enhanced with AI. It conducts static and dynamic analysis and continuously monitors and reports the revealed flaws. Besides, you can integrate it with development tools and processes and prevent vulnerabilities by managing risk and compliance in your system.

GitHub Copilot

GitHub Copilot is an instrument that can assist with identifying potential vulnerabilities in source code. It can help programmers with code reviews and analyze the code for security issues. Besides, GitHubCopilot suggests best practices for secure coding and integrates with automated security tools.

Renovate

Renovate is a great tool that can automate the procedure of updating dependencies. As all dependencies stay updated, it mitigates the vulnerabilities that may exist in outdated libraries. Renovate creates pull requests to update dependencies and ensures that your Java-based app uses the latest, most secure versions of libraries. With this proactive approach, you can maintain security and stability of your application.

SaM Solutions’ seasoned and proactive Java engineering team provides end-to-end Java software development services.

Why SaM Solutions Is the Best Java Development Service Provider?

With 30 years of experience in IT services, SaM Solutions stands out as a trusted partner for businesses worldwide. SaM Solutions has completed over 800 projects for clients ranging from startups to Fortune 500 companies. Whether you need custom enterprise applications, robust web platforms or API integration — our team ensures solutions are crafted to align with your unique business needs. We prioritize securing Java applications​ and follow industry best practices throughout the software development lifecycle. Partner with us to experience high-quality Java solutions that empower your business.

Conclusion: Are Java Apps Secure​?

Java has been recognized as one of the most secure programming languages, and there are lots of reasons for this status. Let’s take its architecture, robust libraries, and focus on safe coding practices — all these characteristics significantly strengthen the level of protection. Nevertheless, you can not guarantee high security just by the language alone. Unpatched components, misconfigurations and logical errors can create gaps that malicious cybercriminals may want to exploit. 

As you know, the nature of cybersecurity is dynamic, and to succeed, you need to be ready to evolve and take a proactive approach in order to ensure that your apps stay resilient against attacks. Implement thorough testing, integrate modern security tools and adhere to the best practices to prevent possible security breaches, and seek advice from professional Java experts at SaM Solutions. Partnering with seasoned Java experts at SaM Solutions will help you maximize the security potential of Java and reap the benefits of our extensive expertise in building secure and scalable apps.