FreeBSD Security Advisory – When replaying setattr transaction, the replay code in ZFS Intent Log would set the attributes with certain insecure defaults, when the logged transaction did not touch these attributes. A system crash or power fail would leave some file with mode set to 07777. This could leak sensitive information or cause privilege escalation.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/84922/FreeBSD-SA-10-03.zfs.txt
Source: https://packetstormsecurity.com/files/84922/FreeBSD-Security-Advisory-ZFS-Insecure-Permissions.html