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Business-critical software applications have been running stably in many companies for years. They reliably perform their tasks and are deeply integrated into core processes. Precisely for this reason, they are rarely the focus of change or security initiatives. At the same time, the threat landscape has become significantly more severe. Cyberattacks are on the rise and are becoming more targeted. The BSI’s latest status report shows that many existing IT and software structures are not sufficiently prepared for today’s attack landscape [1].
This brings a central question to the forefront: How resilient are existing software applications against current threats? Risks often emerge insidiously. Structures that have evolved over years, outdated technologies, and a lack of transparency mean that security issues often go undetected for a long time during ongoing operations.
In many organizations, an unspoken approach applies to existing software applications: as long as an application runs stably, there is no immediate need for changes. These are therefore often deliberately postponed so as not to jeopardize ongoing operations. However, stable operation is not a reliable indicator of security. This is because security vulnerabilities arise regardless of whether an application functions flawlessly and often remain undetected without systematic review. At the same time, the operating environment is constantly changing, while the original architecture and security design are often not designed to accommodate these changes.
In practice, this development repeatedly manifests itself in similar patterns. Applications continue to grow functionally, and new interfaces emerge without the security architecture being adapted to the same extent. Changes are made on an ad hoc basis, while comprehensive documentation is lacking and security audits take place only irregularly. This creates a situation in which software applications appear stable in day-to-day operations, while risks accumulate in the background.
In addition to technical developments, external pressure on companies to systematically secure their software applications is also increasing. The threat landscape has become significantly more severe. Attacks no longer affect only large organizations, but increasingly also medium-sized companies. Applications that have grown organically are particularly targeted, as they are often less well-secured. At the same time, regulatory requirements are growing with guidelines such as NIS-2 or the Cyber Resilience Act (CRA) [2, 3]. Companies must increasingly be able to demonstrate how their software is structured, what risks exist, and what security measures have been implemented.
These requirements affect multiple levels simultaneously. On the one hand, they concern transparency regarding system architecture and dependencies. On the other hand, there is a growing focus on the complete documentation of components in use. Added to this is the need to systematically assess security risks and present them in a traceable manner. This becomes particularly challenging with existing software applications. Dependencies are often only partially documented, components in use are not fully recorded, and the actual security status can only be assessed with considerable effort.
In many cases, the greatest risks arise from structural weaknesses that develop over time. Especially in mature software applications, these risks are often closely intertwined and are rarely considered holistically during ongoing operations.
Many existing software applications are based on technologies that are no longer actively maintained or for which the manufacturers have already discontinued support. In such cases, security updates are no longer available or can only be integrated with considerable effort. At the same time, additional third-party components and libraries are added over the years, and their security status is often not systematically checked.
In many organizations, knowledge of the structure and functionality of software applications is often limited to just a few individuals. This is particularly true of in-house developments that have evolved over time, been continuously expanded over long periods, and are often based on technologies that are now mastered by only a small circle of specialists. This long-standing knowledge is often not fully documented but relies on the experience and personal understanding of those involved. If one of these key individuals becomes unavailable or leaves the company, it becomes critical to reliably continue developing the application or to assess its security.
In addition to technical and organizational aspects, requirements in the areas of cybersecurity and compliance are increasing. Companies must increasingly be able to demonstrate in a transparent manner how their software applications are secured, what risks exist, and how these risks are managed. For audits and inspections, this entails a significant additional burden. Information must be compiled retrospectively, relationships are difficult to trace, and assessments are often based on incomplete data. At the same time, the risk increases that relevant vulnerabilities will be overlooked or cannot be addressed in a timely manner.
How can companies now concretely approach securing their software applications? A complete redevelopment is out of the question for most organizations, as it involves significant effort and substantial costs. Added to this is the concern about disrupting existing, functioning processes. However, continuing operations unchanged also means that existing vulnerabilities remain. Security risks are not actively reduced, while at the same time, cybersecurity and compliance requirements continue to rise. This widens the gap between the application’s current security level and actual requirements.
Against this backdrop, the targeted hardening of existing software applications is gaining importance. Security hardening aims to minimize attack surfaces and systematically close identified vulnerabilities without fundamentally altering the application. The necessary measures can be implemented step by step without interrupting operational processes.
Securing existing software applications requires a structured and transparent approach. The goal is to systematically identify, assess, and specifically mitigate risks without disrupting ongoing operations.
The first step is to develop a comprehensive understanding of the software application. Existing documentation and the practical experience of the individuals involved are combined to create a robust picture of the application. This helps to understand how the application is structured and to identify the initial areas that are particularly critical.
Based on this, potential threats and risks are identified and evaluated in the context of the application. In addition to technical aspects, the use of the application and its importance to business operations are also taken into account. This results in a structured overview of relevant risks and attack scenarios, which enables clear prioritization and serves as a basis for decision-making regarding further measures.
The next step involves a targeted technical analysis. Source code, components in use, and configurations are examined to uncover specific vulnerabilities and compare them with the previously identified risks. This results in a transparent list of identified vulnerabilities, which forms the basis for further evaluation and prioritization.
Based on the analysis, a security hardening concept is developed that describes specific measures to secure the software application. These are prioritized according to urgency and feasibility and incorporated into a structured catalog of measures.
The software application is secured step by step using the previously identified measures. These are implemented specifically where they have the greatest impact on risk reduction without interfering with existing processes. The goal is to continuously improve the security posture without compromising the stability of the application.
Functioning software applications are often perceived as stable and reliable. At the same time, risks arise in the background that remain undetected for a long time and become harder to manage as time goes on. Additionally, the rising threat landscape in cybersecurity, combined with growing compliance requirements, means that existing applications are coming under greater scrutiny.
Companies face the challenge of not only operating their software applications but also actively assessing and enhancing their security levels. A structured security approach creates transparency, reduces risks, and enables companies to develop their software landscape in a future-proof manner. Those who do not actively monitor existing applications risk security issues only becoming apparent once damage has already been done.
Want to know where your existing software really stands? abat’s SMARTsolution Security Hardening provides a structured security analysis, threat modeling, and a concrete hardening concept for your critical applications. At a fixed, predictable price.
Security hardening refers to the targeted hardening of an existing software application without fundamentally restructuring or redeveloping it. This process reduces attack surfaces, closes known vulnerabilities, and optimizes security-related configurations. Unlike a new development, the core of the application remains intact, which significantly reduces effort and protects ongoing operations.
