Here are a few examples on how to exclude some packages from being updated during yum/dnf update:

# yum update --exclude=PACKAGENAME 

Exclude all kernel related packages during update:

# yum update --exclude=kernel*

Exclude gcc and java:

# yum update --exclude=gcc,java

Exclude all gcc and php related packages:

# yum update --exclude=gcc* --exclude=php*

In order to permanently exclude/disable updating of some specific packages you might want to update your dnf.conf or yum.conf eg:

[main]
cachedir=/var/cache/yum/$basearch/$releasever
keepcache=0
debuglevel=2
logfile=/var/log/yum.log
exclude=kernel* php*             <---

Well, the log4j “situation” escalated quickly:

https://gist.github.com/SwitHak/b66db3a06c2955a9cb71a8718970c592

Happy patching everyone.

Go to wordpress’s web directory and simply:

chown -R user:group * 
find . -type d -exec chmod 755 {} \;
find . -type f -exec chmod 644 {} \;

Edit the Postfix’s main.cf file and add the following line (or uncomment it):

header_checks = regexp:/etc/postfix/header_checks

Create /etc/postfix/header_checks file and add the following line:

/^subject:/ WARN

Finally, reload/restart Postfix. From now on there will be a “warrning: header subject” in your maillog.