We're showing some affiliate links (when the recommended merchant happens to be an affiliate), but we're concerned about possible misperceptions of bias.
No, you just need functional tests. Having these kind of bugs in a spare time project is fine, but if you call yourself a startup and ask customers to trust you with data, you need to seriously consider security issues.
I am not a PS guru. All of that is gibberish to me. I think this is what is going on:
1) There is a single source file foo.ps
2) Since PS is interpreted, there is a statement like:
if(filename=="recommendation.ps") { show_recommendation(); }
else { show_give_security_clearance(); }
This attack will work on no matter what hash you use because it uses social engineering (i.e., laziness - no one looks inside their PS files)
Just RTFA'd. Their attack is much more involved than I describe. However, it should be trivial to do the same thing for an OpenOffice document or Word document. Maybe I will try it...