Information
syslog-ng will create logfiles that do not already exist on the system. This setting controls what permissions will be applied to these newly created files.
Rationale:
It is important to ensure that log files exist and have the correct permissions to ensure that sensitive syslog-ng data is archived and protected.
Solution
Edit the /etc/syslog-ng/syslog-ng.conf and set perm option to 0640 or more restrictive:
options { chain_hostnames(off); flush_lines(0); perm(0640); stats_freq(3600); threaded(yes); };