This is the story of probably the least secure CMS ever, at least for the size of it's consumer base. I ran into this many years ago, before I knew anything about how websites work, and the CMS doesn't exist anymore, so I can't really investigate why everything behaved so strangely, but it was strange.

This CMS was a kind of blog platform, except only specially authorised users could view it. It also included hosting. I was helping my friend set it up, and it basically involved sending everybody who was authorized a email with a link to create an account.

The first thing my friend got complaints about was the strange password system. The website had two password boxes, with a limit of (I think) 5 characters each. So when creating a account we recomended people simply insert the first 5 characters in the first box, and the rest in the second. I can not really think of a good explanation for this system, except maybe a shitty way to make sure password are at least 5 characters? Anyway, since this website was insecure the password was emailed to you after the account was created. This is not yet the WTF part.

The CMS forced sidebar with navigation, it also showed the currently logged in users. Except for being unreadable due to a colorful background image, there where many strange behaviors. The sidebar would generally stay even when navigating to external websites. Some internal links would open a second identical sidebar right next to the third. Now, I think that the issue was the main content was in an iframe with the sidebar outside it, but I didn't know about iframe's back then.

So far, we had mostly tested on my friends computer, which was logged in as the blog administrator. At some point, we tried testing with a different account. However, the behavior of sidebars was even stranger now. Now internal links that had previously opened a second, identical sidebar opened a sidebar slightly different from the first: One where the administrator was logged in.

We expirimented somewhat, and found that by clicking links in the second sidebar, we could, with only the login of a random user, change and edit all the settings of the site. Further investigation revealed these urls had a ending like ?user=administrator2J8KZV98YT where administrator was the my friends username. We weren't sure of the exact meaning of the random digits at the end, maybe a hash of the password?

Despite my advice, my friend decided to keep using this CMS. There was also a proper way to do internal links instead of copying the address bar, and he put a warning up not to copy links to on the homepage. Only when the CMS shut down did he finally switch to a system where formatting a link wrong could give anybody admin access.