In FreeBSD 12.2-STABLE before r368250, 11.4-STABLE before r368253, 12.2-RELEASE before p1, 12.1-RELEASE before p11 and 11.4-RELEASE before p5 when processing a DNSSL option, rtsold(8) decodes domain name labels per an encoding specified in RFC 1035 in which the first octet of each label contains the label's length. rtsold(8) did not validate label lengths correctly and could overflow the destination buffer.

In FreeBSD 12.2-STABLE before r368250, 11.4-STABLE before r368253, 12.2-RELEASE before p1, 12.1-RELEASE before p11 and 11.4-RELEASE before p5 rtsold(8) does not verify that the RDNSS option does not extend past the end of the received packet before processing its contents. While the kernel currently ignores such malformed packets, it passes them to userspace programs. Any programs expecting the kernel to do validation may be vulnerable to an overflow.

In FreeBSD 13.0-STABLE before n245118, 12.2-STABLE before r369552, 11.4-STABLE before r369560, 13.0-RC5 before p1, 12.2-RELEASE before p6, and 11.4-RELEASE before p9, a superuser inside a FreeBSD jail configured with the non-default allow.mount permission could cause a race condition between the lookup of ".." and remounting a filesystem, allowing access to filesystem hierarchy outside of the jail.

In FreeBSD 12.2-STABLE before r369346, 11.4-STABLE before r369345, 12.2-RELEASE before p4 and 11.4-RELEASE before p8 a regression in the login.access(5) rule processor has the effect of causing rules to fail to match even when they should not. This means that rules denying access may be ignored.

In FreeBSD 12.2-STABLE before r368969, 11.4-STABLE before r369047, 12.2-RELEASE before p3, 12.1-RELEASE before p13 and 11.4-RELEASE before p7 msdosfs(5) was failing to zero-fill a pair of padding fields in the dirent structure, resulting in a leak of three uninitialized bytes.

In FreeBSD 12.2-STABLE before r368969, 11.4-STABLE before r369047, 12.2-RELEASE before p3, 12.1-RELEASE before p13 and 11.4-RELEASE before p7 several file systems were not properly initializing the doff field of the dirent structures returned by VOPREADDIR. In particular, tmpfs(5), smbfs(5), autofs(5) and mqueuefs(5) were failing to do so. As a result, eight uninitialized kernel stack bytes may be leaked to userspace by these file systems.

In FreeBSD 12.2-STABLE before r369334, 11.4-STABLE before r369335, 12.2-RELEASE before p4 and 11.4-RELEASE before p8 when a process, such as jexec(8) or killall(1), calls jailattach(2) to enter a jail, the jailed root can attach to it using ptrace(2) before the current working directory is changed.

In FreeBSD 12.2-STABLE before r369312, 11.4-STABLE before r369313, 12.2-RELEASE before p4 and 11.4-RELEASE before p8 due to a race condition in the jailremove(2) implementation, it may fail to kill some of the processes.

bhyve, as used in FreeBSD through 12.1 and illumos (e.g., OmniOS CE through r151034 and OpenIndiana through Hipster 2020.04), does not properly restrict VMCS and VMCB read/write operations, as demonstrated by a root user in a container on an Intel system, who can gain privileges by modifying VMCSHOSTRIP.

In FreeBSD 12.2-STABLE before r365767, 11.4-STABLE before r365769, 12.1-RELEASE before p10, 11.4-RELEASE before p4 and 11.3-RELEASE before p14 a number of AMD virtualization instructions operate on host physical addresses, are not subject to nested page table translation, and guest use of these instructions was not trapped.

In FreeBSD 12.2-STABLE before r367402, 11.4-STABLE before r368202, 12.2-RELEASE before p1, 12.1-RELEASE before p11 and 11.4-RELEASE before p5 the handler for a routing option caches a pointer into the packet buffer holding the ICMPv6 message. However, when processing subsequent options the packet buffer may be freed, rendering the cached pointer invalid. The network stack may later dereference the pointer, potentially triggering a use-after-free.

In FreeBSD 12.2-STABLE before r365772, 11.4-STABLE before r365773, 12.1-RELEASE before p10, 11.4-RELEASE before p4 and 11.3-RELEASE before p14 a ftpd(8) bug in the implementation of the file system sandbox, combined with capabilities available to an authenticated FTP user, can be used to escape the file system restriction configured in ftpchroot(5). Moreover, the bug allows a malicious client to gain root privileges.

In FreeBSD 12.2-STABLE before r365730, 11.4-STABLE before r365738, 12.1-RELEASE before p10, 11.4-RELEASE before p4, and 11.3-RELEASE before p14, a programming error in the ure(4) device driver caused some Realtek USB Ethernet interfaces to incorrectly report packets with more than 2048 bytes in a single USB transfer as having a length of only 2048 bytes. An adversary can exploit this to cause the driver to misinterpret part of the payload of a large packet as a separate packet, and thereby inject packets across security boundaries such as VLANs.

In FreeBSD 13.0-STABLE before n246941-20f96f215562, 12.2-STABLE before r370400, 11.4-STABLE before r370399, 13.0-RELEASE before p4, 12.2-RELEASE before p10, and 11.4-RELEASE before p13, certain VirtIO-based device models in bhyve failed to handle errors when fetching I/O descriptors. A malicious guest may cause the device model to operate on uninitialized I/O vectors leading to memory corruption, crashing of the bhyve process, and possibly arbitrary code execution in the bhyve process.

In FreeBSD 13.0-STABLE before n246938-0729ba2f49c9, 12.2-STABLE before r370383, 11.4-STABLE before r370381, 13.0-RELEASE before p4, 12.2-RELEASE before p10, and 11.4-RELEASE before p13, the ggatec daemon does not validate the size of a response before writing it to a fixed-sized buffer allowing a malicious attacker in a privileged network position to overwrite the stack of ggatec and potentially execute arbitrary code.

In FreeBSD 13.0-STABLE before n245117, 12.2-STABLE before r369551, 11.4-STABLE before r369559, 13.0-RC5 before p1, 12.2-RELEASE before p6, and 11.4-RELEASE before p9, copy-on-write logic failed to invalidate shared memory page mappings between multiple processes allowing an unprivileged process to maintain a mapping after it is freed, allowing the process to read private data belonging to other processes or the kernel.

In FreeBSD 13.0-STABLE before n245765-bec0d2c9c841, 12.2-STABLE before r369859, 11.4-STABLE before r369866, 13.0-RELEASE before p1, 12.2-RELEASE before p7, and 11.4-RELEASE before p10, missing message validation in libradius(3) could allow malicious clients or servers to trigger denial of service in vulnerable servers or clients respectively.