FreeBSD: VID-d4d21998-bdc4-4a09-9849-2898d9b41459: zeek -- several vulnerabilities

Tim Wojtulewicz of Corelight reports: Paths from log stream make it into system() unchecked, potentially leading to commands being run on the system unintentionally. This requires either bad scripting or a malicious package to be installed, and is considered low severity. Fix potential unbounded state growth in the PIA analyzer when receiving a connection with either a large number of zero-length packets, or one which continues ack-ing unseen segments. It is possible to run Zeek out of memory in these instances and cause it to crash. Due to the possibility of this happening with packets received from the network, this is a potential DoS vulnerability.