In MidnightBSD before 1.2.6 and 1.3 before August 2020, and FreeBSD before 7, a NULL pointer dereference was found in the Linux emulation layer that allows attackers to crash the running kernel. During binary interaction, td->tdemuldata in sys/compat/linux/linuxemul.h is not getting initialized and returns NULL from emfind().

A memory corruption vulnerability was found in the kernel function kerngetfsstat in MidnightBSD before 1.2.7 and 1.3 through 2020-08-19, and FreeBSD through 11.4, that allows an attacker to trigger an invalid free and crash the system via a crafted size value in conjunction with an invalid mode.

The TCP implementation in (1) Linux, (2) platforms based on BSD Unix, (3) Microsoft Windows, (4) Cisco products, and probably other operating systems allows remote attackers to cause a denial of service (connection queue exhaustion) via multiple vectors that manipulate information in the TCP state table, as demonstrated by sockstress.