The remote host is missing an update to the system as announced in the referenced advisory FreeBSD-SA-03:16.filedesc.asc

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-03:16.filedesc.asc

The readv(2) system call performs a scatter read: it reads from the input file descriptor and stores the data into multiple buffers as instructed by the caller. A programming error in the readv system call can result in the given file descriptor's reference count being erroneously incremented.