TCP Injections for Fun and Clogging

We present a new type of clogging DoS attacks, with the highest amplification factors achieved by off-path attackers, using only puppets, i.e., sandboxed malware on victim machines. Specifically, we present off-path variants of the Opt-ack, Ackstorm and Coremelt DoS attacks, achieving results comparable to these achieved previously achieved by eavesdropping/MitM attackers and (unrestricted) malware. In contrast to previous off-path attacks, which attacked the client (machine) running the malware, our attacks address a very different goal: large-scale clogging DoS of a third party, or even of backbone connections. Our clogging attacks are based on off-path TCP injections. Indeed, as an additional contribution, we present improved off-path TCP injection attacks. Our new attacks significantly relax the requirements cf. to the known attacks; specifically, our injection attack requires only a Java script in browser sandbox (not ‘restricted malware’), does not depend on specific operating system properties, and is efficient even when client’s port is determined using recommended algorithm. Our attacks are constructed modularly, allowing reuse of modules for other scenarios and replacing modules as necessary. We present specific defenses, however, this work is further proof to the need to base security on sound foundations, using cryptography to provide security even against MitM attackers.