Legacy Java Security: What Are the Risks?

legacy java security
Bob Quillin May 4, 2022

Numerous enterprise applications still run on outdated Java technologies, especially the core functionalities. In some cases, businesses are reluctant to move these applications to the cloud because that could make them obsolete. However, these older systems have multiple weak points and security vulnerabilities as cyber security criminals have become more sophisticated.

Let’s look at legacy Java security and the associated risks.

Understanding Legacy Java Security: What Are Legacy Java Systems?

Legacy systems refer to old mainframe terminal applications used in the 80s and 90s, but today many engineers also think of legacy systems as first-generation, web-based business apps developed in the late 1990s.

Legacy systems’ architectures are different, and they face many risks. As such, the modernization of these legacy systems is essential. Types of legacy systems include:

·   Terminal/ mainframe systems

·   Workstation systems (client/server)

·   Browser/ internet systems

Assessing Legacy System Security Concerns

Hacks and breaches can affect any organization, and black hats’ exploitation of these vulnerabilities has become very common. The causes of cyber-attacks and breaches vary widely, and organizations that rely on legacy applications are the most vulnerable to such attacks. 

According to a report by Security Boulevard, there was an increase in severe and critical vulnerabilities to organizations in 2021. Many of these risks involved Java, including personalized vulnerabilities (which predominantly affect all of the apps analyzed in the survey) and weaknesses that resulted in executable file layer attacks.

Throughout May and June of 2021, Java applications were disrupted more by severe vulnerabilities than .NET applications.

Main Risks of Legacy Java Security

Many data centers still have obsolete Java code with well-documented security flaws, leaving businesses vulnerable to attack.

Zero-day attacks are flaws unearthed in software but not yet patched by the supplier. These weaknesses enable viruses to infect your PC without detection by your browser or anti-virus software, and they do not often come from a dangerous website.

A developer can even find an infected script on well-known and genuine websites. This isn’t a brand-new issue for Java.

Related: Application Modernization and Optimization: What Does It Mean?

Some of the risks of legacy Java security include:

Old Security Practices Doesn’t Evolve at the Same Pace as the Threat Landscape

When developing legacy systems, applications had the top cybersecurity practices current at that time. However, the dynamic threat landscape keeps changing, leaving most legacy systems behind.

Some legacy systems become incompatible with modern security features such as role-based access or single-sign-on and multi-factor authentication. They may also have inadequate encryption methods or audit trails. These reasons prevent legacy systems from accommodating the current security best practices.

Additionally, legacy Java security vulnerabilities in software get significant publicity in industry journals and security blogs. Although it’s essential for security professionals to get these updates, hackers receive the same information. This gives cybercriminals adequate tools and knowledge to exploit the documented vulnerabilities in legacy systems.

Outdated Software, Hardware, or Databases Leads to Legacy Dependencies

Besides legacy applications lacking adequate security features, these apps rely on legacy dependencies to function. Some still rely on dated legacy software, mainframe hardware, operating systems, or database structures. These dependencies lead to more security vulnerabilities.

Most organizations that use legacy databases develop multiple mission-critical, proprietary business systems. Over time, the systems become interconnected since they rely on the same legacy databases.

In-house development teams are not security experts, so it’s easy to overlook the best practices for usability and security. The result is spaghetti code that is challenging, if not impossible, to secure and untangle. Due to this complexity, most organizations delay modernizing the code until a security incident makes it mandatory.

Legacy dependencies can also affect the business process by slowing down or preventing successful application modernization initiatives for the cloud.

Legacy Systems Lack True Security Visibility

Spaghetti code in legacy systems often leaves dead code and outdated frameworks in the production environment. Small apps with dated open source code may fail to appear in IT inventories since they don’t contribute to the main business system functionality, and perhaps only a few people still use them.

These apps and tools don’t undergo active development, so they can create security vulnerabilities if not modernized. According to Jaxenter, a Java development magazine, IT security personnel should be very cautious with unpatched software applications.

All applications, regardless of their size, are potentially accessible to cybercriminals. Eliminating any vulnerabilities in the infrastructure reduces this threat. Modern platforms can leverage full-stack security solutions. Businesses should therefore use such platforms offering additional security SLAs to ensure better visibility into security.

Internal Applications Can Have External Exposure Over Time

Despite having reasonable security measures, businesses that use legacy systems develop more vulnerabilities over time. They arise from the software and hardware abandoned after corporate restructuring, mergers, or acquisitions.

Since these assets don’t get decommissioned, although no one is using them, the legacy software or hardware remains in the background. They get exposed to the external world during IT changes and become unsecured access points to cybercriminals looking for such intrusions.

A great example is when FedEx incorporated a company named Bongo. The legacy storage server remained unnoticed when integrating Bongo’s IT assets with the FedEx environment. This left an unsecured Amazon S3 server online within the FedEx network.

Difficulty in Implementing Additional Security Layers

The design in most modern security packages is incompatible with legacy operating systems and mainframe environments. Most legacy applications also often lack instantaneous security monitoring, making it difficult to identify and address security intrusions.

Legacy systems also have inadequate information to offer the true visibility that security experts need. The log functionality and audit trails can be missing or in a challenging format to access and analyze.

In such a case, cybercriminals can exploit legacy applications without creating logs or triggering alerts. They can access the internal network and other systems undetected, and the IT team cannot identify the original access point.

Unlike legacy systems, deploying applications with a hybrid tech stack or a modern cloud allows quick and manageable security solutions. It’s possible to integrate plug-and-play security and network monitoring solutions compatible with your platform.

Related: Why Legacy Application Modernization Is the New Buzzword

How Can Modernizing (Or Refactoring) Mitigate These Risks?

The solution to most legacy security vulnerabilities is modernizing the tech stack. Continuous modernization eliminates possible future technical debt from accumulating and presenting new security attack vectors to bad actors.

Security Threats to Software

Software security is progressively becoming a significant challenge, as software has come to play an essential role in the actual world, and our lifestyles are heavily dependent on it. A device that can connect to open communication systems like the Internet has a piece of code operating on it, swapping data (or objects) or supplying services and applications over the network systems.

Furthermore, various types of mobile source code (for example, a Java applet or JavaScript) are retrieved over the network systems and run on individual computers worldwide. Most software products are vulnerable to vicious enemies in this perspective.

Unprotected software programs, including defenseless code, should be eliminated as much as possible to minimize the risks and exposure posed by threats that try to exploit known vulnerabilities.

In general, two approaches are available for this. One is to build stable software without any vulnerable code–simple, right? If methodologies that sustain the entire software development process are readily accessible, it becomes less possible to unknowingly build software that is vulnerable to threat.

However, designing and implementing secure software in advance is difficult, and replacing all current unprotected programs with freshly created ones takes longer.

Another strategy is to partly modify the style or code of existing software to make it safer. Likely, this will not eliminate threats and risks altogether, but it can reduce the possibility of hazards (such as data manipulation or data breaches) as soon as possible.

Refactoring To Mitigate Risks

All code degrades over time. You will need to refactor it at some stage. Refactoring refers to enhancing code that has deteriorated due to time, adjustments to frameworks and databases, and generally increasing incongruence with the remaining portion of the software.

While this appears essential, developers frequently overlook refactoring during new software development. This results in an alteration of the internal structure of the existing code without changing its observable behavior.

According to Secure Coding, businesses are often hostile to the refactoring idea and refuse to set aside time for this, partly because coders view refactoring as going backward on an already finished project. But refactoring is about much more than repairing broken code. How will your long-term software investments fare if all code ultimately ages?

Modernizing Java is no easy feat because of the complex dependencies and the need for constant regression testing. Therefore, refactoring to improve the design structure while preserving behavior is a typical move to enhance the quality of software systems.

Refactoring can morph into a continuous modernization best practice for coders as code complexity increases. Complexity results because of the addition of unique features, parameters, and specifications. Almost all of the time, refactoring is a reaction to the increasing necessity to revise existing code to ensure it fits into new trends and best practices.

Refactoring is another way of dealing with the mess built up over the years. No script is flawless, but our misconceptions and faulty logic become apparent the more we write.

Refactoring by inference is one option. Developers use this technique whenever there is a considerable quantity of scripts to refactor. Abstraction aims to remove redundancy. Though duplicate code indicates inefficient code, it can lead to security flaws in which one piece of code gets repaired, but the copy is not.

Secure refactoring boosts the safeguards of current code, regardless of how maintainable it is. It identifies vulnerabilities (unintended code flaws) in software programs and eliminates defenseless code or fragile configurations that hackers could use to intentionally or inadvertently harm assets. 

Judging Legacy Java Applications for Refactoring or Discarding

Every organization with multiple Java applications needs to transition to the cloud as part of its application modernization strategy. Modernizing these applications is vital to ensure business continuity and reduce security threats.

However, there are cases where discarding legacy applications is more viable than modernizing them. These insights will help you determine the best course of action based on your specific circumstances.


Java containerization is the process of encapsulating software and all of its dependencies in a solitary, portable bundle. Though not a new principle, containerization is gaining traction thanks to technologies from Docker and the Open Container Initiative that are well suited for cloud deployment.

Beyond operating legacy Java in the context of a modern Java running time, Java containerization offers additional protection. Security protocols execution, for instance, can happen within the (contemporary) Java platform.

Since the controls exist within the JVM, they can be very detailed and application-specific. They can prevent illegal access to particular file system aspects or hinder Java functionalities that aren’t in use by the app but frequently encounter malware infections.

The Ultimate Solution to Legacy Java Security Concerns

Due to Java’s widespread use, comprehensive risk management of Java-related tooling and innovations is critical for ensuring strict protection, whether running a complete CI/CD workflow or just a few internal enterprise internet applications. vFunction offers software solutions that work for you. The platform allows you to learn, assess, refactor, scale, and optimize your Java Applications. You can leverage modernization assessments, monolith transformations, and deep dependency discovery. Schedule a demo today to discover modernization and its various benefits to your organization.