I remember the days of the UBB. Flat file databases, what memories. I also recall UBB getting hacked because the data separator was a pipe bar and the code didn't check for that on input. SQL injection before SQL. Maybe I dreamt that. Either way, I remember my time with flat file databases.
Yup, that was pretty bad. The resulting filtering ended up causing a lot of trouble for folks not using Windows-1252 or something in the ISO-8859 family, as it'd replace pipes in post bodies with the HTML numeric entity for the pipe in that charset. A similar incident is one of the things that got me hired - I was the only one to actually pick up a phone and call their office and talk to tech support about the sheer size of the possible bug.
The most fun security bug the previous major version had was a side effect of file naming. In order to prevent users from just downloading data files, every data file was given the .cgi extension and was always saved as 0777 because shared hosting sucks and nobody ever used suexec like they should.
The file format for user records is the login name on the first line, and the plaintext password on the second, email on the third. Someone figured out that #, ! and / weren't filtered in usernames. See where this is going yet? If the directory containing member records was available inside the document root, someone could perform trivial remote command execution.
The second most fun was people discovering XSS before it was called XSS. With some creative quoting, you could inject javascript into the markup.
I'm just thankful nobody figured out CSRF, I'd have hated to figure out how to deal with that way back then...
