Symantec Endpoint Protection 12.1.6 MP5 addresses important vulnerabilities

Seems even the client needs to be updated (not just the managers) which means you need to have the whole environment upgraded. This requires downtime on each server (normally a reboot if things go well).

https://www.symantec.com/security_response/securityupdates/detail.jsp?fid=security_advisory&pvid=security_advisory&year=&suid=20160628_00

https://support.symantec.com/en_US/article.INFO3801.html

https://support.symantec.com/en_US/article.DOC9352.html

There was another set of vulnerabilities fixed (SYM16-011), for the manager side particularly, in this same release

https://www.symantec.com/security_response/securityupdates/detail.jsp?fid=security_advisory&pvid=security_advisory&year=&suid=20160628_01

Otherwise it does include some fun new capabilities, like certified compatibility with vsphere 6, sql server 2016, and the latest Ubuntu LTS release

Seems Google were the ones to find the vulnerabilities, among others

https://www.engadget.com/2016/06/29/google-symantec-antivirus-flaws-are-as-bad-as-it-gets/

https://googleprojectzero.blogspot.com/2016/06/how-to-compromise-enterprise-endpoint.html 

SEP 12 nugget to stop the service in windows server 2003

You may know that in windows 2003 you can't stop the SEP service from the Services snap-in, but you can from command line:

start smc -stop

or

start smc -start

What I didn't know, and just confirmed today, is that the command only works if the GUI is not running :p