Documentation for Apache 2.4 states that:

> Anyone who can write to the directory where Apache httpd is writing a log file can almost certainly gain access to the uid that the server is started as, which is normally root.

By "the directory where Apache httpd is writing a log file" I assume that they mean the /var/log/httpd directory. On my machine this directory can only be accessed by the root user (I have to "sudo su" to enter that directory). 

Does this mean that a security issue would result if I were to chmod /var/log/httpd to 777? I looks from the documentation that the answer is yes. But I would like to understand better why that is the case. 

How can granting access to the Apache log directory to a non-root user allow that user to gain root access?