Omer Iqbal discovered that Mediawiki, a wiki engine, parses invalid
usernames on Special:PasswordReset as wikitext when $wgRawHtml is
enabled. On such wikis this allows an unauthenticated attacker to
insert malicious JavaScript, a cross site scripting attack.
For the stable distribution (wheezy), this problem has been fixed in
version 1:1.19.16+dfsg-0+deb7u1.
For the unstable distribution (sid), this problem has been fixed in
version 1:1.19.16+dfsg-1.
We recommend that you upgrade your mediawiki packages.