Recent analyses in the cryptocurrency sector highlight emerging security vulnerabilities that put billions of dollars at risk. Experts warn that the traditional distinction between "Web2 Security" and "Web3 Security" is misleading, as decentralized applications (DApps) increasingly integrate both layers, creating overlooked attack surfaces. Cross-chain bridges, designed to unify different blockchains, have become prime targets for hackers due to flawed implementations such as forged proofs and poor key management, resulting in substantial financial losses. In 2024, over 75% of crypto hacks were attributed to internal control failures rather than just smart contract vulnerabilities, prompting a growing emphasis on adopting ISO 27001 standards among Web3 security professionals. Common exploit patterns include reentrancy loops, oracle price manipulation, flash-loan attacks, and weak signature or validation checks, which have been central to major past incidents like the DAO, Wormhole, and Mango hacks. Recent threat intelligence suggests that zero-day vulnerabilities are only the surface of a broader evolution in attacker strategies, underscoring the need for continuous recalibration of security approaches in the crypto ecosystem.