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.

regcomp in the BSD implementation of libc is vulnerable to denial of service due to stack exhaustion.

A vulnerability was discovered in Linux, FreeBSD, OpenBSD, MacOS, iOS, and Android that allows a malicious access point, or an adjacent user, to determine if a connected user is using a VPN, make positive inferences about the websites they are visiting, and determine the correct sequence and acknowledgement numbers in use, allowing the bad actor to inject data into the TCP stream. This provides everything that is needed for an attacker to hijack active connections inside the VPN tunnel.

FreeBSD: Input Validation Flaw allows local users to gain elevated privileges

Information Disclosure vulnerability in the 802.11 stack, as used in FreeBSD before 8.2 and NetBSD when using certain non-x86 architectures. A signedness error in the IEEE80211_IOC_CHANINFO ioctl allows a local unprivileged user to cause the kernel to copy large amounts of kernel memory back to the user, disclosing potentially sensitive information.

FreeBSD NSD before 3.2.13 allows remote attackers to crash a NSD child server process (SIGSEGV) and cause a denial of service in the NSD server.

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.