Not exactly true. phpBB2 has a bad security record. phpBB3 has been clean since day 1, IIRC.
phpBB3 has had a couple tiny problems, but nothing that could be used to attack users of a site or propagate an issue.
But, I have to say that we are very pleased about phpBB3 security...
A presumption that bots wouldn't store+return cookies?
1. visit www.bing.com first
2. search for few random words
3. search those URLs OP mentioned
4. They all works now.
Looks like a bug how Bing handles cookies.
phpbb and topic view are returning error pages for me (on latest ff, cookies enabled).
Another way I'm reliably getting an error page is adding parameter &first=201, e.g. http://www.bing.com/search?q=stuff&first=201
This is the paging parameter, indicating you're at the 20th screen of results.
However, after visiting Bing.com and then clicking on the links, they work.
Either Bing fixed this the same hour his blog post was made, or he just ran into a temporary snag.
And his Google search of the error code on Bing is just that, a snapshot of a temporary error that has no correlation to any particular keyword in the url.
if the exploit supported cookies and could mimic IE it would bypass this form of blocking
Clean history - Bing spits an error, visit bing.com, then search - everything's fine.
You can see the results of the bug on about 50 browsers here:
Ref A: 1868CAC6D8EA4D63B186C4E1C09E8822 Ref B: 22A00154B361421B403038C5A5D4A80F Ref C: Mon Aug 01 17:20:45 2011 PST
Edit: this is under Chrome incognito mode as others have mentioned