Um . . . that *is* a big security hole.
I have patched it.
I also searched the database for evidence that it had been exploited in more serious ways in the past -- I didn't find any evidence that it had been, and the ability to delete comments (and thus erase that evidence) is a recent addition. It's likely that Roncli was the first to find this.
The most serious likely consequences I can think of for the attack are that someone could use it to steal the DCL session credentials of anyone who viewed the page, and access their account until they logged out and back in. Theoretically, anyone with Roncli's skills could have done that and then deleted the comment revealing the attack. I don't think anyone here had the capability and the intent, but I have expired all sessions just to be on the safe side. You'll need to log in again.
Theoretically, it could be a lot worse than that. Together with a vulnerability in another site, this class of attack can allow cross-site monkey business (i.e., accessing your bank), or together with a vulnerability in a browser, it can be used to load malware. I'm pretty sure no such attack was made, but this sort of thing
is kind of a big deal.
Yeah . . . my bad. Thought I'd been rigorous about avoiding that vulnerability. Apparently not.
I do feel the need to point out that posting publicly about it gives everyone seven hours to make a serious attack before I see the message and remove that opportunity. Strictly speaking, proper procedure is to report this sort of thing privately.
But we're all friends here, and you *do* need to be registered on the ladder to *make* the attack . . . so I doubt it was a problem. And I appreciate the prompt report. And I deserve some egg on my face for this one, anyway. In security terms, this is a definite pwn.
Thank you! Glad it was you that found it!