The remote host is missing an update to the system as announced in the referenced advisory FreeBSD-SA-04:02.shmat.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-04:02.shmat.asc

The System V Shared Memory interface provides primitives for sharing memory segments between separate processes. FreeBSD supports this interface when the kernel is built with SYSVSHM option, or the sysvshm module is loaded. By default, the FreeBSD kernel is built with the SYSVSHM option. The shmat(2) system call, which is part of the System V Shared Memory interface, is used to attach a shared memory segment to the calling process's address space. A programming error in the shmat(2) system call can result in a shared memory segment's reference count being erroneously incremented.