In FreeBSD 12.1-STABLE before r359021, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r359020, and 11.3-RELEASE before 11.3-RELEASE-p7, a missing null termination check in the jail_set configuration option "osrelease" may return more bytes with a subsequent jail_get system call allowing a malicious jail superuser with permission to create nested jails to read kernel memory.

In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before 11.3-RELEASE-p7, a TCP SYN-ACK or challenge TCP-ACK segment over IPv6 that is transmitted or retransmitted does not properly initialize the Traffic Class field disclosing one byte of kernel memory over the network.

In FreeBSD 12.1-STABLE before r356089, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r356090, and 11.3-RELEASE before 11.3-RELEASE-p7, driver specific ioctl command handlers in the oce network driver failed to check whether the caller has sufficient privileges allowing unprivileged users to send passthrough commands to the device firmware.

In FreeBSD 12.1-STABLE before r354734, 12.1-RELEASE before 12.1-RELEASE-p2, 12.0-RELEASE before 12.0-RELEASE-p13, 11.3-STABLE before r354735, and 11.3-RELEASE before 11.3-RELEASE-p6, due to incorrect initialization of a stack data structure, core dump files may contain up to 20 bytes of kernel data previously stored on the stack.

In FreeBSD 12.1-STABLE before r357213, 12.1-RELEASE before 12.1-RELEASE-p2, 12.0-RELEASE before 12.0-RELEASE-p13, 11.3-STABLE before r357214, and 11.3-RELEASE before 11.3-RELEASE-p6, URL handling in libfetch with URLs containing username and/or password components is vulnerable to a heap buffer overflow allowing program misbehavior or malicious code execution.

In FreeBSD 12.0-STABLE before r350637, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350638, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the bsnmp library is not properly validating the submitted length from a type-length-value encoding. A remote user could cause an out-of-bounds read or trigger a crash of the software such as bsnmpd resulting in a denial of service.

In FreeBSD 12.0-STABLE before r351264, 12.0-RELEASE before 12.0-RELEASE-p10, 11.3-STABLE before r351265, 11.3-RELEASE before 11.3-RELEASE-p3, and 11.2-RELEASE before 11.2-RELEASE-p14, the kernel driver for /dev/midistat implements a read handler that is not thread-safe. A multi-threaded program can exploit races in the handler to copy out kernel memory outside the boundaries of midistat's data buffer.

In FreeBSD 12.0-STABLE before r350828, 12.0-RELEASE before 12.0-RELEASE-p10, 11.3-STABLE before r350829, 11.3-RELEASE before 11.3-RELEASE-p3, and 11.2-RELEASE before 11.2-RELEASE-p14, a missing check in the function to arrange data in a chain of mbufs could cause data returned not to be contiguous. Extra checks in the IPv6 stack could catch the error condition and trigger a kernel panic, leading to a remote denial of service.

In FreeBSD 12.0-STABLE before r350648, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350650, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the ICMPv6 input path incorrectly handles cases where an MLDv2 listener query packet is internally fragmented across multiple mbufs. A remote attacker may be able to cause an out-of-bounds read or write that may cause the kernel to attempt to access an unmapped page and subsequently panic.

In FreeBSD 12.0-STABLE before r350619, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350619, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the bhyve e1000 device emulation used a guest-provided value to determine the size of the on-stack buffer without validation when TCP segmentation offload is requested for a transmitted packet. A misbehaving bhyve guest could overwrite memory in the bhyve process on the host.