FreeBSD: VID-2ed7e8db-e234-11ea-9392-002590bc43be: sysutils/openzfs-kmod -- critical permissions issues

Andrew Walker reports: Issue 1: Users are always granted permissions to cd into a directory. The check for whether execute is present on directories is a de-facto no-op. This cannot be mitigated without upgrading. Even setting an explicit "deny - execute" NFSv4 ACE will be bypassed. Issue 2: All ACEs for the owner_group (group@) and regular groups (group:<foo>) are granted the current user. This means that POSIX mode 770 is de-facto 777, and the below ACL is also de-facto 777 because the groupmember check for builtin_administrators returns True. root@TESTBOX[~]# getfacl testfile # file: testfile # owner: root # group: wheel group:builtin_administrators:rwxpDdaARWcCos:-------:allow