**Situation:**

* Consider the site: `example.com`, hosted at web server A.
* A WordPress blog is to be installed on a different web server, B.
* In order to route a WordPress installation to a subdirectory on the
main site, e.g. `example.com/blog/`, [most](https://stackoverflow.com/questions/1848605/can-a-website-subdirectory-be-served-by-a-different-web-server) [suggestions](https://stackoverflow.com/questions/3235120/subdirectory-on-a-different-host) on
[StackOverflow](https://stackoverflow.com/questions/6019328/sub-directory-to-a-different-server) recommend to use the Apache `mod_proxy` module, to
set up a reverse proxy.

**Question:**

Is there any security threat to server A (holding customer, credit card, etc. information), or are the usual issues commonly attributed to WordPress mitigated by being on a separate server B?