An Automatic Source Code Vulnerability Detection Approach Based on KELM

Traditional vulnerability detection mostly ran on rules or source code similarity with manually defined vulnerability features. In fact, these vulnerability rules or features are difficult to be defined accurately, which usually cost much expert labor and perform weakly in practical applications. To mitigate this issue, researchers introduced neural networks to automatically extract features to improve the intelligence of vulnerability detection. Bidirectional Long Short-term Memory (Bi-LSTM) network has proved a success for software vulnerability detection. However, due to complex context information processing and iterative training mechanism, training cost is heavy for Bi-LSTM. To effectively improve the training efficiency, we proposed to use Extreme Learning Machine (ELM). -e training process of ELM is noniterative, so the network training can converge quickly. As ELM usually shows weak precision performance because of its simple network structure, we introduce the kernel method. In the preprocessing of this framework, we introduce doc2vec for vector representation and multilevel symbolization for program symbolization. Experimental results show that doc2vec vector representation brings faster training and better generalizing performance than word2vec. ELM converges much quickly than Bi-LSTM, and the kernel method can effectively improve the precision of ELM while ensuring training efficiency.