A new flaw named as NetCAT affects the Intel CPU’s that allows attackers to steal sensitive data from untrusted clients over the network.
NetCAT (Netowork Cache Attack) named by researchers considering the attack triggered in network-based cache side-channel that can leak sensitive data such as keystrokes in an SSH session from remote servers without any physical access.
This vulnerability that mainly resides in the new Intel feature called DDIO, a Data-Direct I/O (DDIO) is a performance-enhancing technology on recent Intel server-grade processors.
Due to the existence of the flaw in DDIO, it grants access for network devices and other peripherals to the CPU cache allows attackers to perform remote side-channel attacks by an untrusted local network.
DDIO has intended to add with Intel server-grade processors to improve the performance and fast cache while performing read/write operation in memory.
“In traditional architectures, where the network card uses direct memory access (DMA) to talk to the operating system, the memory latency alone quickly becomes the bottleneck on fast (e.g., 10Gb/s) networks. To alleviate the bottleneck, Intel introduced DDIO, an architecture where peripherals can operate direct cache access on the CPU’s (last-level) cache.”
An attacker who will successfully perform the NetCAT attack can break the confidentiality of an SSH session remotely without deploying any malicious software on the remote server.
Also, the machine that controlled by the attacker can solely perform this attack by sending network packets to the remote server.
Researchers from vusec successfully tested the NetCAT attack by leak the arrival time of the individual network packets from an SSH session using remote cache side-channel.
In other words, NetCAT Attack leaks the timing of the event (press a key) by leaking the arrival time of the corresponding network packet when the victims type a character inside an encrypted SSH session on your console.
According to VUSec , “we exploit the fact that the DDIO-enabled application server has a shared resource (the last-level cache) between the CPU cores and the network card. We reverse engineered important properties of DDIO to understand how the cache is shared with DDIO. We then use this knowledge to leak sensitive information from the cache of the application server using a cache side-channel attack over the network.”
NetCAT attack can be performed similar to the Throwhammer, and the researchers used the Remote Direct Memory Access (RDMA), a technology that allows their exploit to control the target server memory location of the network packets.
Successful NetCAT attack allows attacker can spy on remote server-side peripherals such as network cards to leak victim data over the network.