The OPC UA implementations (ANSI C and C++) in affected products contain an integer overflow vulnerability that could cause the application to run into an infinite loop during certificate validation. This could allow an unauthenticated remote attacker to create a denial of service condition by sending a specially crafted certificate.
OpenBSD kernel version <= 6.5 can be forced to create long chains of TCP SACK holes that causes very expensive calls to tcpsackoption() for every incoming SACK packet which can lead to a denial of service.