The risk exposure of decentralized finance (DeFi) protocols has been partially addressed by quantitative models, but significant gaps remain. Models like those developed for Aave and Compound assess risks using deposit and borrowing data, capturing volatility and collateral liquidation risks. The "risk wheel" framework categorizes systematic and unsystematic risks, aiding risk assessment. However, DeFi's novelty introduces unique challenges—smart contract vulnerabilities, oracle manipulation, and governance issues often evade full quantification due to their complexity and lack of historical data. Scalability constraints and regulatory uncertainty further complicate modeling. While frameworks exist, comprehensive coverage is limited, requiring ongoing research into protocol interoperability and robust auditing to enhance model accuracy.