Last modified: 2012-11-28 13:55:09 UTC
The latest software upgrade at Wikipedia and other Wikimedia projects
reintroduces an old problem which allows registration of accounts containing
non-printing characters such as &shy;. This can allow vandals to "pretend"
to be someone else. For example, a vandal can regiser a username like
Grunt%C2%AD (not actually using %C2%AD but by placing the non-printing character
in the field...). I registered an account like this by creating a blank HTML
with only the content &­ and then Ctrl+A, Ctrl+C'ing it.
imho the allowed stuff in usernames should be based on a whitelist. Using a
blacklist means that you will always risk missing stuff that vandals would find
See also Bug 2290: user impersonation using homographs for a wider perspective...
bug 1524: usernames should use unicode whitelist
I tried to login within a "#$$%%%%" which throws the login error, "You have not specified a valid user name.". I also tried to do Ctrl^C, Ctrl^V, and other fields that I could think of. The form does allow you to enter illegal characters. So this issue is resolved for now.
I am sorry about the last sentence in the last post. I meant to say I tested and tried to reproduce the error but with no success.
(In reply to comment #4)
> I tried to login within a "#$$%%%%"
These are visible, printable characters. Comment 0 mentions "non-printing characters". See http://en.wikipedia.org/wiki/Non-printing_character
I tried on test2.wikipedia.org (version 1.21wmf5) to create an account as Maly­acko (save as HTML file, open it in browser, copy from the browser display, as described in comment 0).
The name "Malyacko" is not allowed to prevent confusing or spoofed usernames: Contains unassigned character U+00AD. Please choose another name.
So I consider this FIXED as there is a check in place (though I don't know where a blacklist or whitelist is located though, and which exact characters are covered by it).