In FreeBSD 12.1-STABLE before r354734, 12.1-RELEASE before 12.1-RELEASE-p2, 12.0-RELEASE before 12.0-RELEASE-p13, 11.3-STABLE before r354735, and 11.3-RELEASE before 11.3-RELEASE-p6, due to incorrect initialization of a stack data structure, core dump files may contain up to 20 bytes of kernel data previously stored on the stack.
In FreeBSD before 11.1-STABLE, 11.1-RELEASE-p4, 11.0-RELEASE-p15, 10.4-STABLE, 10.4-RELEASE-p3, and 10.3-RELEASE-p24, not all information in the struct ptracelwpinfo is relevant for the state of any thread, and the kernel does not fill the irrelevant bytes or short strings. Since the structure filled by the kernel is allocated on the kernel stack and copied to userspace, a leak of information of the kernel stack of the thread is possible from the debugger. As a result, some bytes from the kernel stack of the thread using ptrace (PTLWPINFO) call can be observed in userspace.
The bsdinstall installer in FreeBSD 10.x before 10.1 p9, when configuring full disk encrypted ZFS, uses world-readable permissions for the GELI keyfile (/boot/encryption.key), which allows local users to obtain sensitive key information by reading the file.
The setlogin function in FreeBSD 8.4 through 10.1-RC4 does not initialize the buffer used to store the login name, which allows local users to obtain sensitive information from kernel memory via a call to getlogin, which returns the entire buffer.
The nullfs implementation in sys/fs/nullfs/nullvnops.c in the kernel in FreeBSD 8.3 through 9.2 allows local users with certain permissions to bypass access restrictions via a hardlink in a nullfs instance to a file in a different instance.
The geli encryption provider 7 before r239184 on FreeBSD 10 uses a weak Master Key, which makes it easier for local users to defeat a cryptographic protection mechanism via a brute-force attack.
crontab.c in crontab in FreeBSD allows local users to determine the existence of arbitrary directories via a command-line argument composed of a directory name concatenated with a directory traversal sequence that leads to the /etc/crontab pathname.
crontab.c in crontab in FreeBSD and Apple Mac OS X allows local users to (1) determine the existence of arbitrary files via a symlink attack on a /tmp/crontab.XXXXXXXXXX temporary file and (2) perform MD5 checksum comparisons on arbitrary pairs of files via two symlink attacks on /tmp/crontab.XXXXXXXXXX temporary files.
FreeBSD 6.3, 6.4, 7.1, and 7.2 does not enforce permissions on the SIOCSIFINFOIN6 IOCTL, which allows local users to modify or disable IPv6 network interfaces, as demonstrated by modifying the MTU.
The ptsname function in FreeBSD 6.0 through 7.0-PRERELEASE does not properly verify that a certain portion of a device name is associated with a pty of a user who is calling the ptchown function, which might allow local users to read data from the pty from another user.