A vulnerability known as “SegmentSmack” was recently discovered in Linux kernels of versions 4.9 or later. An attacker can exploit this vulnerability by remotely sending specially crafted TCP packets to prompt resource-intensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() via open ports, causing CPU saturation and ultimately achieving a denial-of-service (DoS) effect.

It is confirmed that all Nexusguard services are not affected by the vulnerability. We are also working with our vendors on the patching of a few non-critical systems they supply. We recommend customers running affected Linux kernels to apply the patches from the following links:

https://lkml.org/lkml/2018/7/28/40 (Linux 4.9.116)

https://lkml.org/lkml/2018/7/28/44 (Linux 4.17.11)