In FreeBSD before 11.2-STABLE(r338983), 11.2-RELEASE-p4, 11.1-RELEASE-p15, 10.4-STABLE(r338984), and 10.4-RELEASE-p13, due to insufficient initialization of memory copied to userland in the getcontext and swapcontext system calls, small amounts of kernel memory may be disclosed to userland processes. Unprivileged authenticated local users may be able to access small amounts privileged kernel data.

In FreeBSD before 11.2-STABLE(r338986), 11.2-RELEASE-p4, 11.1-RELEASE-p15, 10.4-STABLE(r338985), and 10.4-RELEASE-p13, due to improper maintenance of IPv6 protocol control block flags through various failure paths, an unprivileged authenticated local user may be able to cause a NULL pointer dereference causing the kernel to crash.

In FreeBSD before 11.1-STABLE, 11.2-RELEASE-p3, 11.1-RELEASE-p14, 10.4-STABLE, and 10.4-RELEASE-p12, insufficient validation in the ELF header parser could allow a malicious ELF binary to cause a kernel crash or disclose kernel memory.

One of the data structures that holds TCP segments in all versions of FreeBSD prior to 11.2-RELEASE-p1, 11.1-RELEASE-p12, and 10.4-RELEASE-p10 uses an inefficient algorithm to reassemble the data. This causes the CPU time spent on segment processing to grow linearly with the number of segments in the reassembly queue. An attacker who has the ability to send TCP traffic to a victim system can degrade the victim system's network performance and/or consume excessive CPU by exploiting the inefficiency of TCP reassembly handling, with relatively small bandwidth cost.

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.

Wi-Fi Protected Access (WPA and WPA2) that support 802.11v allows reinstallation of the Integrity Group Temporal Key (IGTK) when processing a Wireless Network Management (WNM) Sleep Mode Response frame, allowing an attacker within radio range to replay frames from access points to clients.

Wi-Fi Protected Access (WPA and WPA2) allows reinstallation of the Station-To-Station-Link (STSL) Transient Key (STK) during the PeerKey handshake, allowing an attacker within radio range to replay, decrypt, or spoof frames.

Wi-Fi Protected Access (WPA and WPA2) allows reinstallation of the Tunneled Direct-Link Setup (TDLS) Peer Key (TPK) during the TDLS handshake, allowing an attacker within radio range to replay, decrypt, or spoof frames.

Wi-Fi Protected Access (WPA and WPA2) that supports IEEE 802.11w allows reinstallation of the Integrity Group Temporal Key (IGTK) during the group key handshake, allowing an attacker within radio range to spoof frames from access points to clients.