Summary
The remote host is missing an update to the system as announced in the referenced advisory FreeBSD-SA-10:03.zfs.asc
Solution
Upgrade your system to the appropriate stable release or security branch dated after the correction date
https://secure1.securityspace.com/smysecure/catid.html?in=FreeBSD-SA-10:03.zfs.asc
Insight
ZFS is a file-system originally developed by Sun Microsystems.
The ZFS Intent Log (ZIL) is a mechanism that gathers together in memory transactions of writes, and is flushed onto disk when synchronous semantics is necessary. In the event of crash or power failure, the log is examined and the uncommitted transaction would be replayed to maintain the synchronous semantics.
When replaying setattr transaction, the replay code would set the attributes with certain insecure defaults, when the logged transaction did not touch these attributes.