Inter-protocol communication

Inter-protocol communication is a security vulnerability in the fundamentals of a network communication protocol. Whilst other protocols are vulnerable, this vulnerability is commonly discussed in the context of the Hypertext Transfer Protocol (HTTP). This attack uses the potential of the two different protocols meaningfully communicating commands and data.

Inter-protocol exploitation can utilize inter-protocol communication to establish the preconditions for launching an Inter-protocol exploit. For example, this process could negotiate the initial authentication communication for a vulnerability in password parsing.

Technical Details

The two protocols involved in the vulnerability are termed the carrier and target. The carrier encapsulates the commands and/or data. The target protocol is used for communication to the intended victim service. Inter-protocol communication will be successful if the carrier protocol can encapsulate the commands and/or data sufficiently to meaningfully communicate to the target service.

Preconditions

Two preconditions need to be met for successful communication across protocols: encapsulation and error tolerance.

Encapsulation

The carrier protocol must encapsulate the data and commands in a manner that the target protocol can understand. It is highly likely that the resulting data stream with induce parsing errors in the target protocol.

Error Tolerance

The target protocol be must be sufficiently forgiving of errors. During the Inter-Protocol connection it is likely that a percentage of the communication will be invalid and cause errors. To meet this precondition, the target protocol implementation must continue processing despite these errors.