Machine Learning-Based Multilabel Classification for Web Application Firewalls: A Comparative Study

The increasing complexity of web-based attacks requires the development of more effective Web Application Firewall (WAF) systems. In this study, we extend previous work by evaluating and comparing the performance of seven machine learning models for multilabel classification of web traffic, using the ECML/PKDD 2007 dataset. This dataset contains eight classes: seven representing different types of attacks and one representing normal traffic. Building on prior experiments that analyzed Recurrent Neural Network (RNN), Gated Recurrent Unit (GRU), and Long Short-Term Memory (LSTM) models, we incorporate four additional models frequently cited in the related literature: Random Forest (RF), Support Vector Machine (SVM), Gradient Boosting (GB), and Feedforward Neural Networks (NN). Each model is trained and evaluated under consistent preprocessing and validation protocols. We analyze their performance using key metrics such as accuracy, precision, recall, F1-score, and training time. The results provide insights into the suitability of each method for WAF classification tasks, with implications for real-time intrusion detection systems and security automation. This study represents the first unified multilabel evaluation of classical and deep learning approaches on the ECML/PKDD 2007 dataset, offering guidance for practical WAF deployment.