Donncha has announced the new release of WordPress MU (1.3.3). This release fixes the same flaw in XML-RPC as the WordPress core release.
We recommend you update your WP-MU to the latest version or atleast upgrade your xmlrpc.php file.
And hopefully people aren’t using WordPress MU
Donncha, why is that?
Ooops. Looks like my comment got cut off. “earlier than 1.3.2″ should be appended to that statement.
Unfortunately for 1.3.3 the options system got revamped, so really, the only way to be safe is to upgrade.