Systems and methods in accordance with various embodiments of the present disclosure provide secure filtering of transactions at a hardware and protocol level using a security device included on a server. In particular, various embodiments provide approaches for filtering transactions on various buses, such as SMBus, PMBus, I2C, and SPI, within a server. This filtering logic can be utilized to modify requests for access to devices on those busses, certain memory or registers within the devices, and/or limit the quantity of transactions on those busses. Embodiments may provide a policy engine through which the filtering logic applied to a given bus or buses may be modified. When a transaction is received, one or more attributes of the transaction can be compared to one or more policies. If there is a match, the transaction can be modified according to the matched policy.