The security patches introduced in version 0.7.2 are now also available for users of version 0.6. Version 0.5.2 might also work, but lower versions should really be updated.
So if you want to stick to an older version of OpenBiblio for a while, you can simply overwrite some files with the newer ones supplied in the attached zipfile. (0.5.2 users should omit layout.php)
Diff: