Linux Vulnerabilities Issues!

Hii All,

I am back again! With some questions and doubts!
I was trying to find a way to do some research on linux systems vulnerabilities!

Recently I was accessing my shared hosting servers raw access logs and other audit data! I found some logs with some not-so-familiar strings! While doing some searches on google I came to a concept that these might reflect unix/linux system vulnerabilites.

One of the strings contained denied access from an un-familiar ip (to me) to
/cgi-bin/.htaccess , how and why would someone try this? Can anyone give any hint please?

Regards