DeFi protocols handle significant financial value, and the wallet integration layer is a potential attack surface if it is not built with security as a foundational constraint. The categories of vulnerability most relevant to DeFi wallet integrations include approval manipulation, where malicious code intercepts approval transactions and substitutes a higher amount or different spender address than the user intended; transaction substitution, where the transaction presented to the user for signing differs from the transaction submitted to the network; and session compromise, where an attacker captures a connected wallet session and uses it to initiate unauthorized transactions.
27 Blockchain addresses each of these vulnerability categories in DeFi wallet integration projects through implementation practices and audit processes that are part of the standard integration scope. Transaction integrity verification ensures that what the user sees in the wallet signing interface matches what is submitted to the network. Approval amount and spender address validation prevents approval manipulation at the integration layer before the approval transaction reaches the wallet. Smart contract code that is part of the integration scope, including any contracts the wallet integration calls or approves, is audited against the vulnerability patterns most commonly exploited in DeFi deployments. The security architecture 27 Blockchain builds into DeFi wallet integration projects reflects the financial stakes of the protocols being integrated.
