A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures Software Developer's Manual (SDM) was mishandled in the development of some or all operating-system kernels, resulting in unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS, as demonstrated by (for example) privilege escalation in Windows, macOS, some Xen configurations, or FreeBSD, or a Linux kernel crash. The MOV to SS and POP SS instructions inhibit interrupts (including NMIs), data breakpoints, and single step trap exceptions until the instruction boundary following the next instruction (SDM Vol. 3A; section 6.8.3). (The inhibited data breakpoints are those on memory accessed by the MOV to SS or POP to SS instruction itself.) Note that debug exceptions are not inhibited by the interrupt enable (EFLAGS.IF) system flag (SDM Vol. 3A; section 2.3). If the instruction following the MOV to SS or POP to SS instruction is an instruction like SYSCALL, SYSENTER, INT 3, etc. that tra…

In FreeBSD before 11.0-STABLE, 11.0-RELEASE-p10, 10.3-STABLE, and 10.3-RELEASE-p19, ipfilter using "keep state" or "keep frags" options can cause a kernel panic when fed specially crafted packet fragments due to incorrect memory handling.

In FreeBSD before 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8 and 10.3-RELEASE-p28, due to insufficient initialization of memory copied to userland, small amounts of kernel memory may be disclosed to userland processes. Unprivileged users may be able to access small amounts privileged kernel data.

In FreeBSD before 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8 and 10.3-RELEASE-p28, the length field of the ipsec option header does not count the size of the option header itself, causing an infinite loop when the length is zero. This issue can allow a remote attacker who is able to send an arbitrary packet to cause the machine to crash.

In FreeBSD before 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8 and 10.3-RELEASE-p28, insufficient validation of user-provided font parameters can result in an integer overflow, leading to the use of arbitrary kernel memory as glyph data. Unprivileged users may be able to access privileged kernel data.

In FreeBSD before 11.1-STABLE, 11.1-RELEASE-p7, 10.4-STABLE, 10.4-RELEASE-p7, and 10.3-RELEASE-p28, the kernel does not properly validate IPsec packets coming from a trusted host. Additionally, a use-after-free vulnerability exists in the IPsec AH handling code. This issue could cause a system crash or other unpredictable results.

Buffer overflow in the decodearr function in ntpq in ntp 4.2.8p6 through 4.2.8p10 allows remote attackers to execute arbitrary code by leveraging an ntpq query and sending a response with a crafted array.

The routed daemon in FreeBSD 9.3 before 9.3-RELEASE-p22, 10.2-RC2 before 10.2-RC2-p1, 10.2-RC1 before 10.2-RC1-p2, 10.2 before 10.2-BETA2-p3, and 10.1 before 10.1-RELEASE-p17 allows remote authenticated users to cause a denial of service (assertion failure and daemon exit) via a query from a network that is not directly connected.

Larry Wall's patch; patch in FreeBSD 10.2-RC1 before 10.2-RC1-p1, 10.2 before 10.2-BETA2-p2, and 10.1 before 10.1-RELEASE-p16; Bitrig; GNU patch before 2.2.5; and possibly other patch variants allow remote attackers to execute arbitrary shell commands via a crafted patch file.

The do_ed_script function in pch.c in GNU patch through 2.7.6, and patch in FreeBSD 10.1 before 10.1-RELEASE-p17, 10.2 before 10.2-BETA2-p3, 10.2-RC1 before 10.2-RC1-p2, and 0.2-RC2 before 10.2-RC2-p1, allows remote attackers to execute arbitrary commands via a crafted patch file, because a '!' character can be passed to the ed program.