Samba-3.0.24 was released yesterday to fix 3 security vulnerabilities.  Anyone running an older version should take a look at the release notes and seriously consider upgrading (there are also patches against 3.0.23d available on the Samba site).

References:
http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-0452
http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-0453
http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-0454
http://news.samba.org/releases/3.0.24/