An issue was discovered in OpenSSH 7.9. Due to the scp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the scp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious scp server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the scp client target directory. If recursive operation (-r) is performed, the server can manipulate subdirectories as well (for example, to overwrite the .ssh/authorized_keys file).

In FreeBSD before 11.2-STABLE(r341486) and 11.2-RELEASE-p6, insufficient bounds checking in one of the device models provided by bhyve can permit a guest operating system to overwrite memory in the bhyve host possibly permitting arbitrary code execution. A guest OS using a firmware image can cause the bhyve process to crash, or possibly execute arbitrary code on the host as root.

In FreeBSD before 11.2-STABLE(r340854) and 11.2-RELEASE-p5, the NFS server lacks a bounds check in the READDIRPLUS NFS request. Unprivileged remote users with access to the NFS server can cause a resource exhaustion by forcing the server to allocate an arbitrarily large memory allocation.

In FreeBSD before 11.2-STABLE(r340854) and 11.2-RELEASE-p5, an integer overflow error can occur when handling the client address length field in an NFSv4 request. Unprivileged remote users with access to the NFS server can crash the system by sending a specially crafted NFSv4 request.

In FreeBSD before 11.2-STABLE(r340854) and 11.2-RELEASE-p5, an integer overflow error when handling opcodes can cause memory corruption by sending a specially crafted NFSv4 request. Unprivileged remote users with access to the NFS server may be able to execute arbitrary code.

In FreeBSD before 11.2-STABLE(r340268) and 11.2-RELEASE-p5, due to incorrectly accounting for padding on 64-bit platforms, a buffer underwrite could occur when constructing an ICMP reply packet when using a non-standard value for the net.inet.icmp.quotelen sysctl.

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 11.2-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(r338987), 11.2-RELEASE-p4, and 11.1-RELEASE-p15, due to insufficient memory checking in the freebsd4_getfsstat system call, a NULL pointer dereference can occur. Unprivileged authenticated local users may be able to cause a denial of service.

In FreeBSD before 11.2-RELEASE, an application which calls setrlimit() to increase RLIMIT_STACK may turn a read-only memory region below the stack into a read-write region. A specially crafted executable could be exploited to execute arbitrary code in the user context.

In FreeBSD before 11.2-RELEASE, multiple issues with the implementation of the stack guard-page reduce the protections afforded by the guard-page. This results in the possibility a poorly written process could be cause a stack overflow.

In FreeBSD before 11.2-RELEASE, a stack guard-page is available but is disabled by default. This results in the possibility a poorly written process could be cause a stack overflow.

In FreeBSD 11.x before 11.1-RELEASE and 10.x before 10.4-RELEASE, the qsort algorithm has a deterministic recursion pattern. Feeding a pathological input to the algorithm can lead to excessive stack usage and potential overflow. Applications that use qsort to handle large data set may crash if the input follows the pathological pattern.

Improper bounds checking of the obuf variable in the link_ntoa() function in linkaddr.c of the BSD libc library may allow an attacker to read or write from memory. The full impact and severity depends on the method of exploit and how the library is used by applications. According to analysis by FreeBSD developers, it is very unlikely that applications exist that utilize link_ntoa() in an exploitable manner, and the CERT/CC is not aware of any proof of concept. A blog post describes the functionality of link_ntoa() and points out that none of the base utilities use this function in an exploitable manner. For more information, please see FreeBSD Security Advisory SA-16:37.

In FreeBSD before 11.1-STABLE(r332303), 11.1-RELEASE-p10, 10.4-STABLE(r332321), and 10.4-RELEASE-p9, due to insufficient initialization of memory copied to userland in the Linux subsystem and Atheros wireless driver, small amounts of kernel memory may be disclosed to userland processes. Unprivileged authenticated local users may be able to access small amounts of privileged kernel data.

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.

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.