Funnily enough, I have just put this in and it seems to be working pretty well:
#!/bin/sh
#
############################################################################
# Extension Attribute to display Security for Mac application version.
#
############################################################################
SEPVersion=/usr/bin/defaults read /Applications/Symantec Solutions/Symantec Endpoint Protection.app/Contents/Info CFBundleShortVersionString
echo "<result> v$SEPVersion </result>"
exit 0
What Treger said...that is working for me in 9.63.
I also use this one to show the last virus definition date:
#Check to see if SEP v12 is installed
SEPVERSION=$(/usr/bin/defaults read /Applications/Symantec Solutions/Symantec Endpoint Protection.app/Contents/Info CFBundleShortVersionString)
SEPVERSIONSHORT=${SEPVERSION:0:2}
if [ "$SEPVERSIONSHORT" == "12" ];
then
SEP12DEFINITIONSDIR=$(ls -td /Library/Application Support/Symantec/AntiVirus/*/ | grep -m 1 AntiVirus)
WHATSNEW="$SEP12DEFINITIONSDIR""WHATSNEW.txt"
RESULT12=$(/bin/date -j -f "%b %d, %Y" "$(cat "$WHATSNEW" | grep "Symantec Security Response" | awk '{print $5, $6, $7}')" "+%Y-%m-%d 00:00:00")
echo "<result>$RESULT12</result>"
exit 0
fi