In software, a vulnerability is a defect in a program that attackers might utilize to acquire unauthorized access, alter system functions, and acquire information. These vulnerabilities arise from programming faults, design flaws, incorrect setups, and a lack of security protective measures. To mitigate these vulnerabilities, regular software upgrades, code reviews, safe development techniques, and the use of security tools to find and fix problems have been important. Several ways have been delivered in recent studies to address difficulties related to software vulnerabilities. However, previous approaches have significant limitations, notably in feature embedding and precisely recognizing specific vulnerabilities. To overcome these drawbacks, we present CodeGraphNet, an experimental method that combines GraphCodeBERT and Graph Convolutional Network (GCN) approaches, where, CodeGraphNet reveals data in a high-dimensional vector space, with comparable or related properties grouped closer together. This method captures intricate relationships between features, providing for more exact identification and separation of vulnerabilities. Using this feature embedding approach, we employed four machine learning models, applying both independent testing and 10-fold cross-validation. The DeepTree model, which is a hybrid of a Decision Tree and a Neural Network, outperforms state-of-the-art approaches. In additional validation, we evaluated our model using feature embeddings from LSA, GloVe, FastText, CodeBERT and GraphCodeBERT, and found that the CodeGraphNet method presented improved vulnerability identification with 98% of accuracy. Our model was tested on a real-time dataset to determine its capacity to handle real-world data and to focus on defect localization, which might influence future studies.

Software security is crucial in any field where breaches can exploit sensitive data, and lead to financial losses. As a result, vulnerability detection becomes an essential part of the software development process. One of the key steps in maintaining software integrity is identifying vulnerabilities in the source code before deployment. A security breach like CWE-476, which stands for NULL pointer dereferences (NPD), is crucial because it can cause software crashes, unpredictable behavior, and security vulnerabilities. In this scientific era, there are several vulnerability checkers, where, previous tools often fall short in analyzing specific feature connections of the source code, which weakens the tools in real-world scenarios. In this study, we propose another novel approach using a fine-tuned Large Language Model (LLM) termed "DeLLNeuN". This model leverages the advantage of various layers to reduce both overfitting and non-linearity, enhancing its performance and reliability. Additionally, this method provides dropout and dimensionality reduction to help streamline the model, making it faster and more efficient. Our model showed 87% accuracy with 88% precision using the Draper VDISC dataset. As software becomes more complex and cyber threats continuously evolve, the need for proactive security measures will keep growing. In this particular case, the proposed model looks promising to use as an early vulnerability checker in software development.