There are two things you should consider in this piece of code:
The first one is the type of the variable pwStatus, the second one is the value of the strcmp return address.
The goal is to overwrite the strcmp return address to make the pwStatus variable to be always true, because of pwStatus variable could only be true or false; So, if the ASCII code of one ...
why would a web server developer/admin decide to enable loading external xml entities in the first place?
Usually this is not about explicitly enabling but about not being aware of the problem and using a library with insecure default settings. Many libraries have or had loading of external entities enabled by default. To cite from OWASP XML External ...
Like the other committers says: it is dependent on the implementation of the httpLibrary.get.
You can simplify the httpLibrary.get to a function, it can do anything from just NOP to run a complete job. Before the shellshock the programmers would not notice that environment variable could cause the RCE.
You can follow the OWASP Top 10 - A1 Injection: always ...
This depends on what you could do with an injection; article would be of your choice, but this needn't be helpful.
Nonetheless, if httpLibrary.get does take a URL string, you can easily inject this and return arbitrary data for article:
Setting articleId to @yourdomain.tld/yourpath should make everything in front of it a user name for http basic auth.