Summary
The remote host is missing an update to the system as announced in the referenced advisory.
Solution
Update your system with the appropriate patches or software upgrades.
https://git.torproject.org/checkout/tor/master/ChangeLog http://www.vuxml.org/freebsd/f59dda75-5ff4-11de-a13e-00e0815b8da8.html
Insight
The following package is affected: tor-devel