The e1000 network adapters permit a variety of modifications to an Ethernet packet when it is being transmitted. These include the insertion of IP and TCP checksums, insertion of an Ethernet VLAN header, and TCP segmentation offload ("TSO"). The e1000 device model uses an on-stack buffer to generate the modified packet header when simulating these modifications on transmitted packets. When checksum offload is requested for a transmitted packet, the e1000 device model used a guest-provided value to specify the checksum offset in the on-stack buffer. The offset was not validated for certain packet types. A misbehaving bhyve guest could overwrite memory in the bhyve process on the host, possibly leading to code execution in the host context. The bhyve process runs in a Capsicum sandbox, which (depending on the FreeBSD version and bhyve configuration) limits the impact of exploiting this issue.

Handlers for *_CFG_PAGE read / write ioctls in the mpr, mps, and mpt drivers allocated a buffer of a caller-specified size, but copied to it a fixed size header. Other heap content would be overwritten if the specified size was too small. Users with access to the mpr, mps or mpt device node may overwrite heap data, potentially resulting in privilege escalation. Note that the device node is only accessible to root and members of the operator group.

A user-provided integer option was passed to nmreq_copyin() without checking if it would overflow. This insufficient bounds checking could lead to kernel memory corruption. On systems configured to include netmap in their devfs_ruleset, a privileged process running in a jail can affect the host environment.

The total size of the user-provided nmreq to nmreq_copyin() was first computed and then trusted during the copyin. This time-of-check to time-of-use bug could lead to kernel memory corruption. On systems configured to include netmap in their devfs_ruleset, a privileged process running in a jail can affect the host environment.

When GELI reads a key file from standard input, it does not reuse the key file to initialize multiple providers at once resulting in the second and subsequent devices silently using a NULL key as the user key file. If a user only uses a key file without a user passphrase, the master key is encrypted with an empty key file allowing trivial recovery of the master key.

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.