In FreeBSD 11.3-PRERELEASE before r345378, 12.0-STABLE before r345377, 11.2-RELEASE before 11.2-RELEASE-p10, and 12.0-RELEASE before 12.0-RELEASE-p4, a bug in pf does not check if the outer ICMP or ICMP6 packet has the same destination IP as the source IP of the inner protocol packet allowing a maliciously crafted ICMP/ICMP6 packet could bypass the packet filter rules and be passed to a host that would otherwise be unavailable.

The implementations of SAE in hostapd and wpasupplicant are vulnerable to side channel attacks as a result of observable timing differences and cache access patterns. An attacker may be able to gain leaked information from a side channel attack that can be used for full password recovery. Both hostapd with SAE support and wpasupplicant with SAE support prior to and including version 2.7 are affected.

In FreeBSD before 11.2-STABLE(r340854) and 11.2-RELEASE-p5, the NFS server lacks a bounds check in the READDIRPLUS NFS request. Unprivileged remote users with access to the NFS server can cause a resource exhaustion by forcing the server to allocate an arbitrarily large memory allocation.

In FreeBSD before 11.2-STABLE(r340854) and 11.2-RELEASE-p5, an integer overflow error can occur when handling the client address length field in an NFSv4 request. Unprivileged remote users with access to the NFS server can crash the system by sending a specially crafted NFSv4 request.

In FreeBSD before 11.2-STABLE(r341486) and 11.2-RELEASE-p6, insufficient bounds checking in one of the device models provided by bhyve can permit a guest operating system to overwrite memory in the bhyve host possibly permitting arbitrary code execution. A guest OS using a firmware image can cause the bhyve process to crash, or possibly execute arbitrary code on the host as root.

In FreeBSD before 11.2-STABLE(r340268) and 11.2-RELEASE-p5, due to incorrectly accounting for padding on 64-bit platforms, a buffer underwrite could occur when constructing an ICMP reply packet when using a non-standard value for the net.inet.icmp.quotelen sysctl.

In FreeBSD before 11.2-STABLE(r348229), 11.2-RELEASE-p7, 12.0-STABLE(r342228), and 12.0-RELEASE-p1, insufficient validation of network-provided data in bootpd may make it possible for a malicious attacker to craft a bootp packet which could cause a stack buffer overflow. It is possible that the buffer overflow could lead to a Denial of Service or remote code execution.

In FreeBSD 12.0-STABLE before r350246, 12.0-RELEASE before 12.0-RELEASE-p8, 11.3-STABLE before r350247, 11.3-RELEASE before 11.3-RELEASE-p1, and 11.2-RELEASE before 11.2-RELEASE-p12, the emulated XHCI device included with the bhyve hypervisor did not properly validate data provided by the guest, allowing an out-of-bounds read. This provides a malicious guest the possibility to crash the system or access system memory.

In FreeBSD 12.0-STABLE before r347474, 12.0-RELEASE before 12.0-RELEASE-p7, 11.2-STABLE before r347475, and 11.2-RELEASE before 11.2-RELEASE-p11, a bug in the FFS implementation causes up to three bytes of kernel stack memory to be written to disk as uninitialized directory entry padding.

In FreeBSD 12.0-STABLE before r349622, 12.0-RELEASE before 12.0-RELEASE-p7, 11.3-PRERELEASE before r349624, 11.3-RC3 before 11.3-RC3-p1, and 11.2-RELEASE before 11.2-RELEASE-p11, a bug in iconv implementation may allow an attacker to write past the end of an output buffer. Depending on the implementation, an attacker may be able to create a denial of service, provoke incorrect program behavior, or induce a remote code execution.

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 r350261, 12.0-RELEASE before 12.0-RELEASE-p8, 11.3-STABLE before r350263, 11.3-RELEASE before 11.3-RELEASE-p1, and 11.2-RELEASE before 11.2-RELEASE-p12, system calls operating on file descriptors as part of mqueuefs did not properly release the reference allowing a malicious user to overflow the counter allowing access to files, directories, and sockets opened by processes owned by other users.

In FreeBSD 11.3-PRERELEASE and 12.0-STABLE before r347591, 11.2-RELEASE before 11.2-RELEASE-p10, and 12.0-RELEASE before 12.0-RELEASE-p4, a bug in the pf IPv6 fragment reassembly logic incorrectly uses the last extension header offset from the last received packet instead of the first packet allowing maliciously crafted IPv6 packets to cause a crash or potentially bypass the packet filter.

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 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 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.

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 11.3-STABLE before r350217, 11.3-RELEASE before 11.3-RELEASE-p1, and 11.2-RELEASE before 11.2-RELEASE-p12, due to insufficient initialization of memory copied to userland in the freebsd32ioctl interface, small amounts of kernel memory may be disclosed to userland processes. This may allow an attacker to leverage this information to obtain elevated privileges either directly or indirectly.

In FreeBSD 12.0-STABLE before r349628, 12.0-RELEASE before 12.0-RELEASE-p7, 11.3-PRERELEASE before r349629, 11.3-RC3 before 11.3-RC3-p1, and 11.2-RELEASE before 11.2-RELEASE-p11, a bug in the cdrom driver allows users with read access to the cdrom device to arbitrarily overwrite kernel memory when media is present thereby allowing a malicious user in the operator group to gain root privileges.